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math-013101
Number Theory: Divisibility — Linear Combinations
7
Determine the requested value: (a) Compute $\gcd(1615,984)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1615+v\cdot 984=\gcd(1615,984)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. ...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1615,984)$ to compute $g=\\gcd(1615,984)$.", "Step 2: Record the remainder...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=223,v=-366$ satisfies $u1615+v984=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustn...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013102
Number Theory: Units mod m — Existence Condition
7
Track quantifiers carefully: Find the multiplicative inverse of $599$ modulo $989$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{989}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(599,989)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{530}$.\nMethod 1 constructs an inverse via Bézout, producing $x=530$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: ...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{530}$.)
math-013103
Number Theory: Divisibility — Linear Combinations
7
Derive the result step-by-step: (a) Compute $\gcd(1312,1875)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1312+v\cdot 1875=\gcd(1312,1875)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution cha...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1312,1875)$ to compute $g=\\gcd(1312,1875)$.", "Step 2: Record the remaind...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=373,v=-261$ satisfies $u1312+v1875=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis"...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013104
Number Theory: Units mod m — Existence Condition
7
Give reasoning, not just computation: Find the multiplicative inverse of $121$ modulo $420$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{420}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient cond...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=361$ and compute $121x=43681$.", "Step 2: Reduce: $43681\\equiv 1\\pmod{420}$ (since $43680=43680$ is divis...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{361}$.\nMethod 1 constructs an inverse via Bézout, producing $x=361$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Extended Euclid is fast...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{361}$.)
math-013105
Number Theory: Modular Inverses — Extended Euclid
7
Make each step logically reversible (or explain if not): Find the multiplicative inverse of $110$ modulo $273$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{273}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary ...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=206$ and compute $110x=22660$.", "Step 2: Reduce: $22660\\equiv 1\\pmod{273}$ (since $22659=22659$ is divis...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{206}$.\nMethod 1 constructs an inverse via Bézout, producing $x=206$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analy...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013106
Number Theory: gcd — Euclidean Algorithm
7
Make each step logically reversible (or explain if not): (a) Compute $\gcd(790,988)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 790+v\cdot 988=\gcd(790,988)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backwa...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(790,988)$ to compute $g=\\gcd(790,988)$.", "Step 2: Record the remainder e...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=-5,v=4$ satisfies $u790+v988=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013107
Number Theory: gcd — Euclidean Algorithm
7
Work this out carefully: (a) Compute $\gcd(757,1788)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 757+v\cdot 1788=\gcd(757,1788)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Inclu...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=385$ and $v=-163$ with $u757...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=385,v=-163$ satisfies $u757+v1788=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: Euclid scales...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013108
Number Theory: Congruences — Solving $ax\equiv 1$
7
Solve (and briefly cross-validate): Find the multiplicative inverse of $1006$ modulo $1103$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1103}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient con...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=705$ and compute $1006x=709230$.", "Step 2: Reduce: $709230\\equiv 1\\pmod{1103}$ (since $709229=709229$ is...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{705}$.\nMethod 1 constructs an inverse via Bézout, producing $x=705$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Extended Euclid is fast...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{705}$.)
math-013109
Number Theory: gcd — Back Substitution
7
Find the exact value: (a) Compute $\gcd(1073,1444)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1073+v\cdot 1444=\gcd(1073,1444)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Inclu...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=397$ and $v=-295$ with $u107...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=397,v=-295$ satisfies $u1073+v1444=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: Euclid ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013110
Number Theory: Bézout Identity — Certificates
7
Work this out carefully: (a) Compute $\gcd(236,1193)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 236+v\cdot 1193=\gcd(236,1193)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Inclu...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-551$ and $v=109$ with $u236...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-551,v=109$ satisfies $u236+v1193=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis":...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013111
Number Theory: Modular Inverses — Extended Euclid
7
Work carefully and justify each inference: Find the multiplicative inverse of $54$ modulo $137$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{137}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient ...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=33$ and compute $54x=1782$.", "Step 2: Reduce: $1782\\equiv 1\\pmod{137}$ (since $1781=1781$ is divisible b...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{33}$.\nMethod 1 constructs an inverse via Bézout, producing $x=33$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were perturbed: Exten...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{33}$.)
math-013112
Number Theory: gcd — Back Substitution
7
Give an answer and a quick verification: (a) Compute $\gcd(762,238)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 762+v\cdot 238=\gcd(762,238)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution ...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(762,238)$ to compute $g=\\gcd(762,238)$.", "Step 2: Record the remainder e...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=5,v=-16$ satisfies $u762+v238=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Ge...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013113
Computational Number Theory: Inverses and Certificates
7
Answer with a short justification: Find the multiplicative inverse of $16$ modulo $51$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{51}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition ...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(16,51)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such that ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{16}$.\nMethod 1 constructs an inverse via Bézout, producing $x=16$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Extended Euclid is ...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{16}$.)
math-013114
Number Theory: gcd — Back Substitution
7
Indicate where a theorem is used: (a) Compute $\gcd(1396,1695)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1396+v\cdot 1695=\gcd(1396,1695)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution c...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1396,1695)$ to compute $g=\\gcd(1396,1695)$.", "Step 2: Record the remaind...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-839,v=691$ satisfies $u1396+v1695=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: Euclid scale...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013115
Computational Number Theory: Inverses and Certificates
7
Give an answer and a quick verification: Find the multiplicative inverse of $60$ modulo $161$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{161}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient co...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=51$ and compute $60x=3060$.", "Step 2: Reduce: $3060\\equiv 1\\pmod{161}$ (since $3059=3059$ is divisible b...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{51}$.\nMethod 1 constructs an inverse via Bézout, producing $x=51$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysi...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013116
Computational Number Theory: Extended Euclid
7
State any required conditions first: (a) Compute $\gcd(1630,646)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1630+v\cdot 646=\gcd(1630,646)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution c...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1630,646)$ to compute $g=\\gcd(1630,646)$.", "Step 2: Record the remainder...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=-86,v=217$ satisfies $u1630+v646=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness note: Euclid scales ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{2}$.)
math-013117
Number Theory: Divisibility — Linear Combinations
7
Warm-up: (a) Compute $\gcd(969,861)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 969+v\cdot 861=\gcd(969,861)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include a brief verifica...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(969,861)$ to compute $g=\\gcd(969,861)$.", "Step 2: Record the remainder e...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{3}$.\nThe Euclidean algorithm computes $g=3$. The Bézout certificate $u=8,v=-9$ satisfies $u969+v861=3$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Rob...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Takeaway: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013118
Number Theory: Bézout Identity — Certificates
7
Do not skip justification steps: (a) Compute $\gcd(702,1676)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 702+v\cdot 1676=\gcd(702,1676)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(702,1676)$ to compute $g=\\gcd(702,1676)$.", "Step 2: Record the remainder...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=191,v=-80$ satisfies $u702+v1676=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: Euclid s...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{2}$.)
math-013119
Number Theory: Units mod m — Existence Condition
7
Show all reasoning: Find the multiplicative inverse of $259$ modulo $1195$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1195}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inv...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=729$ and compute $259x=188811$.", "Step 2: Reduce: $188811\\equiv 1\\pmod{1195}$ (since $188810=188810$ is ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{729}$.\nMethod 1 constructs an inverse via Bézout, producing $x=729$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysis: Extended Euc...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013120
Number Theory: gcd — Back Substitution
7
Give reasoning, not just computation: (a) Compute $\gcd(978,1404)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 978+v\cdot 1404=\gcd(978,1404)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution ...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-89$ and $v=62$ with $u978+v...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{6}$.\nThe Euclidean algorithm computes $g=6$. The Bézout certificate $u=-89,v=62$ satisfies $u978+v1404=6$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were pertur...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{6}$.)
math-013121
Number Theory: Divisibility — Linear Combinations
7
Give a fully justified solution: (a) Compute $\gcd(279,612)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 279+v\cdot 612=\gcd(279,612)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. ...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(279,612)$ to compute $g=\\gcd(279,612)$.", "Step 2: Record the remainder e...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{9}$.\nThe Euclidean algorithm computes $g=9$. The Bézout certificate $u=11,v=-5$ satisfies $u279+v612=9$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Ge...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{9}$.)
math-013122
Number Theory: Modular Inverses — Extended Euclid
7
Track units/moduli carefully: Find the multiplicative inverse of $172$ modulo $761$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{761}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition fo...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(172,761)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{615}$.\nMethod 1 constructs an inverse via Bézout, producing $x=615$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analy...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{615}$.)
math-013123
Number Theory: Divisibility — Linear Combinations
7
Complete the analysis: (a) Compute $\gcd(1940,1786)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1940+v\cdot 1786=\gcd(1940,1786)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Incl...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=58$ and $v=-63$ with $u1940+...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=58,v=-63$ satisfies $u1940+v1786=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: Euclid sc...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013124
Number Theory: gcd — Euclidean Algorithm
7
Derive the result step-by-step: (a) Compute $\gcd(211,102)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 211+v\cdot 102=\gcd(211,102)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. I...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(211,102)$ to compute $g=\\gcd(211,102)$.", "Step 2: Record the remainder e...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-29,v=60$ satisfies $u211+v102=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: Euclid scales ef...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013125
Number Theory: Divisibility — Linear Combinations
7
Checkpoint: (a) Compute $\gcd(1835,1074)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1835+v\cdot 1074=\gcd(1835,1074)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include a brief...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1835,1074)$ to compute $g=\\gcd(1835,1074)$.", "Step 2: Record the remaind...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-175,v=299$ satisfies $u1835+v1074=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were perturbed...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013126
Number Theory: Units mod m — Existence Condition
7
Track units/moduli carefully: Find the multiplicative inverse of $183$ modulo $853$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{853}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition fo...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=289$ and compute $183x=52887$.", "Step 2: Reduce: $52887\\equiv 1\\pmod{853}$ (since $52886=52886$ is divis...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{289}$.\nMethod 1 constructs an inverse via Bézout, producing $x=289$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysis: Extended Euc...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013127
Computational Number Theory: Inverses and Certificates
7
Answer with a short justification: Find the multiplicative inverse of $1352$ modulo $1539$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1539}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient cond...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(1352,1539)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such t...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{716}$.\nMethod 1 constructs an inverse via Bézout, producing $x=716$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustne...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{716}$.)
math-013128
Number Theory: Divisibility — Linear Combinations
7
Try to avoid pattern-matching; explain why: (a) Compute $\gcd(986,164)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 986+v\cdot 164=\gcd(986,164)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substituti...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=1$ and $v=-6$ with $u986+v16...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=1,v=-6$ satisfies $u986+v164=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness n...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{2}$.)
math-013129
Number Theory: Modular Inverses — Extended Euclid
7
Use two approaches if possible: Find the multiplicative inverse of $105$ modulo $172$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{172}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition ...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(105,172)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{77}$.\nMethod 1 constructs an inverse via Bézout, producing $x=77$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysis: Extended Euclid is f...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{77}$.)
math-013130
Computational Number Theory: Inverses and Certificates
7
Proceed methodically: Find the multiplicative inverse of $135$ modulo $1487$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1487}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an i...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(135,1487)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such th...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{738}$.\nMethod 1 constructs an inverse via Bézout, producing $x=738$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Extended Euclid is fast...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013131
Number Theory: Bézout Identity — Certificates
7
Solve and include a self-check: (a) Compute $\gcd(1107,1217)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1107+v\cdot 1217=\gcd(1107,1217)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution cha...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1107,1217)$ to compute $g=\\gcd(1107,1217)$.", "Step 2: Record the remaind...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-520,v=473$ satisfies $u1107+v1217=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Takeaway: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013132
Number Theory: Modular Inverses — Extended Euclid
7
Keep the final answer in boxed form: Find the multiplicative inverse of $4$ modulo $229$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{229}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient conditi...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(4,229)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such that ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{172}$.\nMethod 1 constructs an inverse via Bézout, producing $x=172$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the p...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013133
Number Theory: Bézout Identity — Certificates
7
Give a theorem-based solution: (a) Compute $\gcd(1557,1132)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1557+v\cdot 1132=\gcd(1557,1132)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chai...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1557,1132)$ to compute $g=\\gcd(1557,1132)$.", "Step 2: Record the remaind...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=285,v=-392$ satisfies $u1557+v1132=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis"...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013134
Number Theory: Units mod m — Existence Condition
7
Challenge: Find the multiplicative inverse of $93$ modulo $1864$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1864}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to ex...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(93,1864)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{461}$.\nMethod 1 constructs an inverse via Bézout, producing $x=461$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Extended Euclid is fast...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013135
Number Theory: Congruences — Solving $ax\equiv 1$
7
Solve and sanity-check: Find the multiplicative inverse of $1350$ modulo $1537$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1537}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for a...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=600$ and compute $1350x=810000$.", "Step 2: Reduce: $810000\\equiv 1\\pmod{1537}$ (since $809999=809999$ is...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{600}$.\nMethod 1 constructs an inverse via Bézout, producing $x=600$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitiv...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013136
Computational Number Theory: Inverses and Certificates
7
Question: Find the multiplicative inverse of $42$ modulo $53$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{53}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to exist. ...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(42,53)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such that ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{24}$.\nMethod 1 constructs an inverse via Bézout, producing $x=24$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were perturbed: Extended Eu...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{24}$.)
math-013137
Number Theory: Modular Inverses — Extended Euclid
7
Be explicit about assumptions: Find the multiplicative inverse of $239$ modulo $640$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{640}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition f...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(239,640)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{399}$.\nMethod 1 constructs an inverse via Bézout, producing $x=399$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Extended Euclid i...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{399}$.)
math-013138
Number Theory: Bézout Identity — Certificates
7
State any required conditions first: (a) Compute $\gcd(943,387)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 943+v\cdot 387=\gcd(943,387)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chai...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(943,387)$ to compute $g=\\gcd(943,387)$.", "Step 2: Record the remainder e...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-158,v=385$ satisfies $u943+v387=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustne...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013139
Number Theory: gcd — Back Substitution
7
Do not skip justification steps: (a) Compute $\gcd(1025,1157)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1025+v\cdot 1157=\gcd(1025,1157)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution ch...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=149$ and $v=-132$ with $u102...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=149,v=-132$ satisfies $u1025+v1157=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis"...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013140
Number Theory: Units mod m — Existence Condition
7
Track quantifiers carefully: Find the multiplicative inverse of $1085$ modulo $1289$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1289}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition ...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=714$ and compute $1085x=774690$.", "Step 2: Reduce: $774690\\equiv 1\\pmod{1289}$ (since $774689=774689$ is...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{714}$.\nMethod 1 constructs an inverse via Bézout, producing $x=714$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysis: Extended Euc...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{714}$.)
math-013141
Number Theory: Divisibility — Linear Combinations
7
Solve with verification: (a) Compute $\gcd(605,1398)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 605+v\cdot 1398=\gcd(605,1398)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Inclu...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-409$ and $v=177$ with $u605...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-409,v=177$ satisfies $u605+v1398=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis":...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013142
Computational Number Theory: Extended Euclid
7
Question: (a) Compute $\gcd(1400,1283)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1400+v\cdot 1283=\gcd(1400,1283)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include a brief v...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1400,1283)$ to compute $g=\\gcd(1400,1283)$.", "Step 2: Record the remaind...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-318,v=347$ satisfies $u1400+v1283=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensit...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013143
Number Theory: gcd — Euclidean Algorithm
7
Try to avoid pattern-matching; explain why: (a) Compute $\gcd(204,215)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 204+v\cdot 215=\gcd(204,215)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substituti...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=39$ and $v=-37$ with $u204+v...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=39,v=-37$ satisfies $u204+v215=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the pro...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Takeaway: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013144
Number Theory: Modular Inverses — Extended Euclid
7
Question: Find the multiplicative inverse of $745$ modulo $933$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{933}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to exis...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=799$ and compute $745x=595255$.", "Step 2: Reduce: $595255\\equiv 1\\pmod{933}$ (since $595254=595254$ is d...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{799}$.\nMethod 1 constructs an inverse via Bézout, producing $x=799$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Extended Euclid is fast...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013145
Computational Number Theory: Inverses and Certificates
7
Give a fully justified solution: Find the multiplicative inverse of $21$ modulo $671$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{671}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition ...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(21,671)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such that...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{32}$.\nMethod 1 constructs an inverse via Bézout, producing $x=32$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{32}$.)
math-013146
Computational Number Theory: Extended Euclid
7
Solve and sanity-check: (a) Compute $\gcd(139,1142)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 139+v\cdot 1142=\gcd(139,1142)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Includ...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(139,1142)$ to compute $g=\\gcd(139,1142)$.", "Step 2: Record the remainder...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-419,v=51$ satisfies $u139+v1142=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were pertu...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Takeaway: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013147
Computational Number Theory: Extended Euclid
7
Determine the requested value: (a) Compute $\gcd(807,1343)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 807+v\cdot 1343=\gcd(807,1343)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. ...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-223$ and $v=134$ with $u807...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-223,v=134$ satisfies $u807+v1343=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness note: Euclid ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013148
Computational Number Theory: Extended Euclid
7
Answer with a short justification: (a) Compute $\gcd(957,455)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 957+v\cdot 455=\gcd(957,455)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain....
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(957,455)$ to compute $g=\\gcd(957,455)$.", "Step 2: Record the remainder e...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=213,v=-448$ satisfies $u957+v455=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: Euc...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013149
Computational Number Theory: Extended Euclid
7
Question: (a) Compute $\gcd(1839,442)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1839+v\cdot 442=\gcd(1839,442)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include a brief veri...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1839,442)$ to compute $g=\\gcd(1839,442)$.", "Step 2: Record the remainder...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=193,v=-803$ satisfies $u1839+v442=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "General...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013150
Number Theory: gcd — Back Substitution
7
Provide both a computational and a conceptual explanation: (a) Compute $\gcd(216,885)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 216+v\cdot 885=\gcd(216,885)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear back...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-127$ and $v=31$ with $u216+...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{3}$.\nThe Euclidean algorithm computes $g=3$. The Bézout certificate $u=-127,v=31$ satisfies $u216+v885=3$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generalit...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{3}$.)
math-013151
Computational Number Theory: Inverses and Certificates
7
Give a fully justified solution: Find the multiplicative inverse of $479$ modulo $715$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{715}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(479,715)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{409}$.\nMethod 1 constructs an inverse via Bézout, producing $x=409$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were perturbed: Extended ...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{409}$.)
math-013152
Number Theory: Bézout Identity — Certificates
7
Make each step logically reversible (or explain if not): (a) Compute $\gcd(133,1414)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 133+v\cdot 1414=\gcd(133,1414)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear bac...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(133,1414)$ to compute $g=\\gcd(133,1414)$.", "Step 2: Record the remainder...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{7}$.\nThe Euclidean algorithm computes $g=7$. The Bézout certificate $u=-85,v=8$ satisfies $u133+v1414=7$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013153
Number Theory: gcd — Euclidean Algorithm
7
Do not skip justification steps: (a) Compute $\gcd(1172,1862)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1172+v\cdot 1862=\gcd(1172,1862)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution ch...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=367$ and $v=-231$ with $u117...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=367,v=-231$ satisfies $u1172+v1862=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were per...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{2}$.)
math-013154
Number Theory: gcd — Euclidean Algorithm
7
Checkpoint: (a) Compute $\gcd(1664,1599)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1664+v\cdot 1599=\gcd(1664,1599)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include a brief...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1664,1599)$ to compute $g=\\gcd(1664,1599)$.", "Step 2: Record the remaind...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{13}$.\nThe Euclidean algorithm computes $g=13$. The Bézout certificate $u=-49,v=51$ satisfies $u1664+v1599=13$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{13}$.)
math-013155
Number Theory: Divisibility — Linear Combinations
7
Task: (a) Compute $\gcd(1539,1621)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1539+v\cdot 1621=\gcd(1539,1621)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include a brief verif...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1539,1621)$ to compute $g=\\gcd(1539,1621)$.", "Step 2: Record the remaind...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-257,v=244$ satisfies $u1539+v1621=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: E...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013156
Computational Number Theory: Inverses and Certificates
7
Provide both a computational and a conceptual explanation: Find the multiplicative inverse of $904$ modulo $1621$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1621}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necess...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=1569$ and compute $904x=1418376$.", "Step 2: Reduce: $1418376\\equiv 1\\pmod{1621}$ (since $1418375=1418375...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1569}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1569$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity ana...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{1569}$.)
math-013157
Number Theory: Units mod m — Existence Condition
7
Problem: Find the multiplicative inverse of $263$ modulo $298$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{298}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to exist...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(263,298)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{17}$.\nMethod 1 constructs an inverse via Bézout, producing $x=17$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Extended Euclid is fast a...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013158
Number Theory: Divisibility — Linear Combinations
7
Start by stating any domain restrictions: (a) Compute $\gcd(545,583)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 545+v\cdot 583=\gcd(545,583)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=46$ and $v=-43$ with $u545+v...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=46,v=-43$ satisfies $u545+v583=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness note: Euclid scales ef...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013159
Computational Number Theory: Inverses and Certificates
7
Checkpoint: Find the multiplicative inverse of $445$ modulo $946$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{946}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to ex...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(445,946)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{625}$.\nMethod 1 constructs an inverse via Bézout, producing $x=625$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the p...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013160
Number Theory: gcd — Back Substitution
7
Try to avoid pattern-matching; explain why: (a) Compute $\gcd(1969,213)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1969+v\cdot 213=\gcd(1969,213)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substit...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1969,213)$ to compute $g=\\gcd(1969,213)$.", "Step 2: Record the remainder...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-86,v=795$ satisfies $u1969+v213=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were perturbed: ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Takeaway: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013161
Number Theory: Bézout Identity — Certificates
7
Work carefully and justify each inference: (a) Compute $\gcd(1366,850)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1366+v\cdot 850=\gcd(1366,850)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitu...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-28$ and $v=45$ with $u1366+...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=-28,v=45$ satisfies $u1366+v850=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the pr...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{2}$.)
math-013162
Number Theory: Modular Inverses — Extended Euclid
7
Solve and include a self-check: Find the multiplicative inverse of $1305$ modulo $1576$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1576}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient conditi...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=977$ and compute $1305x=1274985$.", "Step 2: Reduce: $1274985\\equiv 1\\pmod{1576}$ (since $1274984=1274984...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{977}$.\nMethod 1 constructs an inverse via Bézout, producing $x=977$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were perturbed: Extended ...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{977}$.)
math-013163
Number Theory: gcd — Euclidean Algorithm
7
Give a fully justified solution: (a) Compute $\gcd(463,1370)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 463+v\cdot 1370=\gcd(463,1370)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(463,1370)$ to compute $g=\\gcd(463,1370)$.", "Step 2: Record the remainder...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=577,v=-195$ satisfies $u463+v1370=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: Euclid ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013164
Number Theory: Congruences — Solving $ax\equiv 1$
7
Challenge: Find the multiplicative inverse of $268$ modulo $337$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{337}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to exi...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=210$ and compute $268x=56280$.", "Step 2: Reduce: $56280\\equiv 1\\pmod{337}$ (since $56279=56279$ is divis...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{210}$.\nMethod 1 constructs an inverse via Bézout, producing $x=210$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the p...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{210}$.)
math-013165
Number Theory: Bézout Identity — Certificates
7
State any required conditions first: (a) Compute $\gcd(194,1106)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 194+v\cdot 1106=\gcd(194,1106)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution c...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-57$ and $v=10$ with $u194+v...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=-57,v=10$ satisfies $u194+v1106=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Takeaway: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013166
Number Theory: Units mod m — Existence Condition
7
Warm-up: Find the multiplicative inverse of $605$ modulo $791$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{791}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to exist...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(605,791)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{404}$.\nMethod 1 constructs an inverse via Bézout, producing $x=404$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem we...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{404}$.)
math-013167
Number Theory: gcd — Euclidean Algorithm
7
Be explicit about assumptions: (a) Compute $\gcd(1427,1552)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1427+v\cdot 1552=\gcd(1427,1552)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chai...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1427,1552)$ to compute $g=\\gcd(1427,1552)$.", "Step 2: Record the remaind...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-149,v=137$ satisfies $u1427+v1552=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: E...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013168
Number Theory: Modular Inverses — Extended Euclid
7
Try to avoid pattern-matching; explain why: Find the multiplicative inverse of $547$ modulo $935$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{935}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficien...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(547,935)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{788}$.\nMethod 1 constructs an inverse via Bézout, producing $x=788$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were perturbed: Ext...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013169
Number Theory: gcd — Back Substitution
7
Give an answer and a quick verification: (a) Compute $\gcd(1067,396)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1067+v\cdot 396=\gcd(1067,396)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substituti...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=13$ and $v=-35$ with $u1067+...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{11}$.\nThe Euclidean algorithm computes $g=11$. The Bézout certificate $u=13,v=-35$ satisfies $u1067+v396=11$, and divisibility shows no larger common divisor can exist.", "robustness_analysis"...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013170
Number Theory: gcd — Back Substitution
7
Challenge: (a) Compute $\gcd(939,1197)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 939+v\cdot 1197=\gcd(939,1197)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include a brief ver...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(939,1197)$ to compute $g=\\gcd(939,1197)$.", "Step 2: Record the remainder...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{3}$.\nThe Euclidean algorithm computes $g=3$. The Bézout certificate $u=-116,v=91$ satisfies $u939+v1197=3$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were perturbed: ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013171
Number Theory: Units mod m — Existence Condition
7
Task: Find the multiplicative inverse of $413$ modulo $1549$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1549}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to exist....
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=1534$ and compute $413x=633542$.", "Step 2: Reduce: $633542\\equiv 1\\pmod{1549}$ (since $633541=633541$ is...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1534}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1534$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Extended Euclid is fa...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{1534}$.)
math-013172
Number Theory: Modular Inverses — Extended Euclid
7
Explain each transformation: Find the multiplicative inverse of $355$ modulo $421$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{421}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(355,421)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{236}$.\nMethod 1 constructs an inverse via Bézout, producing $x=236$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem we...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{236}$.)
math-013173
Computational Number Theory: Inverses and Certificates
7
Solve and then verify: Find the multiplicative inverse of $832$ modulo $1731$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1731}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an ...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(832,1731)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such th...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{310}$.\nMethod 1 constructs an inverse via Bézout, producing $x=310$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Extended Euclid is fast...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{310}$.)
math-013174
Number Theory: Modular Inverses — Extended Euclid
7
Solve (and briefly cross-validate): Find the multiplicative inverse of $241$ modulo $331$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{331}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condit...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=114$ and compute $241x=27474$.", "Step 2: Reduce: $27474\\equiv 1\\pmod{331}$ (since $27473=27473$ is divis...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{114}$.\nMethod 1 constructs an inverse via Bézout, producing $x=114$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Extended Euclid i...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{114}$.)
math-013175
Computational Number Theory: Inverses and Certificates
7
Solve and include a self-check: Find the multiplicative inverse of $889$ modulo $1369$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1369}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient conditio...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(889,1369)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such th...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{482}$.\nMethod 1 constructs an inverse via Bézout, producing $x=482$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem we...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{482}$.)
math-013176
Number Theory: gcd — Back Substitution
7
Solve with verification: (a) Compute $\gcd(1563,1654)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1563+v\cdot 1654=\gcd(1563,1654)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. In...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1563,1654)$ to compute $g=\\gcd(1563,1654)$.", "Step 2: Record the remaind...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-309,v=292$ satisfies $u1563+v1654=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were perturbed...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013177
Computational Number Theory: Inverses and Certificates
7
Where appropriate, name the theorem you use: Find the multiplicative inverse of $1564$ modulo $1703$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1703}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and suffi...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=49$ and compute $1564x=76636$.", "Step 2: Reduce: $76636\\equiv 1\\pmod{1703}$ (since $76635=76635$ is divi...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{49}$.\nMethod 1 constructs an inverse via Bézout, producing $x=49$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013178
Computational Number Theory: Inverses and Certificates
7
Task: Find the multiplicative inverse of $763$ modulo $823$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{823}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to exist. ...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=96$ and compute $763x=73248$.", "Step 2: Reduce: $73248\\equiv 1\\pmod{823}$ (since $73247=73247$ is divisi...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{96}$.\nMethod 1 constructs an inverse via Bézout, producing $x=96$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Extended Euclid is ...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{96}$.)
math-013179
Number Theory: Congruences — Solving $ax\equiv 1$
7
Start by stating any domain restrictions: Find the multiplicative inverse of $185$ modulo $1477$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1477}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficien...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=495$ and compute $185x=91575$.", "Step 2: Reduce: $91575\\equiv 1\\pmod{1477}$ (since $91574=91574$ is divi...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{495}$.\nMethod 1 constructs an inverse via Bézout, producing $x=495$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysis: Extended Euclid is...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013180
Number Theory: Bézout Identity — Certificates
7
Track quantifiers carefully: (a) Compute $\gcd(1432,104)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1432+v\cdot 104=\gcd(1432,104)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. I...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=4$ and $v=-55$ with $u1432+v...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{8}$.\nThe Euclidean algorithm computes $g=8$. The Bézout certificate $u=4,v=-55$ satisfies $u1432+v104=8$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{8}$.)
math-013181
Number Theory: Units mod m — Existence Condition
7
Keep the final answer in boxed form: Find the multiplicative inverse of $580$ modulo $921$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{921}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condi...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(580,921)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{316}$.\nMethod 1 constructs an inverse via Bézout, producing $x=316$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analy...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{316}$.)
math-013182
Computational Number Theory: Inverses and Certificates
7
Make each step logically reversible (or explain if not): Find the multiplicative inverse of $20$ modulo $1877$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1877}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(20,1877)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{657}$.\nMethod 1 constructs an inverse via Bézout, producing $x=657$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysis: Extended Euclid is...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{657}$.)
math-013183
Number Theory: Modular Inverses — Extended Euclid
7
Complete the analysis: Find the multiplicative inverse of $584$ modulo $1251$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1251}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an ...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=422$ and compute $584x=246448$.", "Step 2: Reduce: $246448\\equiv 1\\pmod{1251}$ (since $246447=246447$ is ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{422}$.\nMethod 1 constructs an inverse via Bézout, producing $x=422$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustne...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{422}$.)
math-013184
Number Theory: Congruences — Solving $ax\equiv 1$
7
Find the exact value: Find the multiplicative inverse of $29$ modulo $1952$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1952}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an in...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(29,1952)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1077}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1077$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Genera...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{1077}$.)
math-013185
Number Theory: Divisibility — Linear Combinations
7
Solve (and briefly cross-validate): (a) Compute $\gcd(907,471)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 907+v\cdot 471=\gcd(907,471)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=148$ and $v=-285$ with $u907...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=148,v=-285$ satisfies $u907+v471=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-013186
Computational Number Theory: Extended Euclid
7
Do not skip justification steps: (a) Compute $\gcd(1620,863)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1620+v\cdot 863=\gcd(1620,863)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-57$ and $v=107$ with $u1620...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-57,v=107$ satisfies $u1620+v863=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness note: Euclid scales ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013187
Number Theory: Modular Inverses — Extended Euclid
7
Solve with verification: Find the multiplicative inverse of $482$ modulo $525$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{525}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an ...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=293$ and compute $482x=141226$.", "Step 2: Reduce: $141226\\equiv 1\\pmod{525}$ (since $141225=141225$ is d...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{293}$.\nMethod 1 constructs an inverse via Bézout, producing $x=293$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: ...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{293}$.)
math-013188
Number Theory: Congruences — Solving $ax\equiv 1$
7
Make each step logically reversible (or explain if not): Find the multiplicative inverse of $158$ modulo $247$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{247}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary ...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(158,247)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such tha...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{111}$.\nMethod 1 constructs an inverse via Bézout, producing $x=111$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analy...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{111}$.)
math-013189
Computational Number Theory: Inverses and Certificates
7
Solve and justify each step: Find the multiplicative inverse of $854$ modulo $1523$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1523}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition f...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=708$ and compute $854x=604632$.", "Step 2: Reduce: $604632\\equiv 1\\pmod{1523}$ (since $604631=604631$ is ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{708}$.\nMethod 1 constructs an inverse via Bézout, producing $x=708$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Extended Euclid i...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013190
Number Theory: Divisibility — Linear Combinations
7
Determine the requested value: (a) Compute $\gcd(1841,226)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1841+v\cdot 226=\gcd(1841,226)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. ...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1841,226)$ to compute $g=\\gcd(1841,226)$.", "Step 2: Record the remainder...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-89,v=725$ satisfies $u1841+v226=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the p...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Takeaway: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013191
Number Theory: Modular Inverses — Extended Euclid
7
Exercise: Find the multiplicative inverse of $138$ modulo $1673$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1673}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition for an inverse to ex...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(138,1673)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such th...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{885}$.\nMethod 1 constructs an inverse via Bézout, producing $x=885$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were perturbed: Extended ...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{885}$.)
math-013192
Number Theory: Bézout Identity — Certificates
7
Where appropriate, name the theorem you use: (a) Compute $\gcd(1896,124)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1896+v\cdot 124=\gcd(1896,124)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substi...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=7$ and $v=-107$ with $u1896+...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{4}$.\nThe Euclidean algorithm computes $g=4$. The Bézout certificate $u=7,v=-107$ satisfies $u1896+v124=4$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: Euclid sca...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Remember: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{4}$.)
math-013193
Computational Number Theory: Extended Euclid
7
Find the exact value: (a) Compute $\gcd(1150,200)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1150+v\cdot 200=\gcd(1150,200)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include ...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1150,200)$ to compute $g=\\gcd(1150,200)$.", "Step 2: Record the remainder...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{50}$.\nThe Euclidean algorithm computes $g=50$. The Bézout certificate $u=-1,v=6$ satisfies $u1150+v200=50$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{50}$.)
math-013194
Number Theory: gcd — Back Substitution
7
Solve and then verify: (a) Compute $\gcd(531,1281)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 531+v\cdot 1281=\gcd(531,1281)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. Include...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(531,1281)$ to compute $g=\\gcd(531,1281)$.", "Step 2: Record the remainder...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{3}$.\nThe Euclidean algorithm computes $g=3$. The Bézout certificate $u=193,v=-80$ satisfies $u531+v1281=3$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": ...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013195
Number Theory: gcd — Euclidean Algorithm
7
Work this out carefully: (a) Compute $\gcd(1077,1255)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1077+v\cdot 1255=\gcd(1077,1255)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitution chain. In...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=-557$ and $v=478$ with $u107...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-557,v=478$ satisfies $u1077+v1255=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis"...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013196
Number Theory: gcd — Euclidean Algorithm
7
Try to avoid pattern-matching; explain why: (a) Compute $\gcd(1414,526)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1414+v\cdot 526=\gcd(1414,526)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substit...
[ { "method_name": "Bézout + Divisibility Argument", "approach": "Use the definition of gcd as the smallest positive linear combination and show any common divisor divides your combination.", "steps": [ "Step 1: From the extended Euclidean algorithm we obtain integers $u=93$ and $v=-250$ with $u1414...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=93,v=-250$ satisfies $u1414+v526=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: Euclid s...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Core principle: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$.
math-013197
Number Theory: Congruences — Solving $ax\equiv 1$
7
Where appropriate, name the theorem you use: Find the multiplicative inverse of $879$ modulo $1240$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1240}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and suffic...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(879,1240)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such th...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{79}$.\nMethod 1 constructs an inverse via Bézout, producing $x=79$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013198
Computational Number Theory: Extended Euclid
7
Provide both a computational and a conceptual explanation: (a) Compute $\gcd(1668,410)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1668+v\cdot 410=\gcd(1668,410)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear b...
[ { "method_name": "Euclidean Algorithm + Back-Substitution", "approach": "Compute the gcd by repeated division, then reverse the steps to express the gcd as a linear combination.", "steps": [ "Step 1: Apply Euclid to $(1668,410)$ to compute $g=\\gcd(1668,410)$.", "Step 2: Record the remainder...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=44,v=-179$ satisfies $u1668+v410=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitivity analysis: Euc...
[ { "error_description": "Stopped Euclid early and used the last remainder before reaching 0.", "why_plausible": "The repeated division process is easy to truncate accidentally.", "why_wrong": "The gcd is the last nonzero remainder; stopping early yields a multiple of the gcd, not necessarily the gcd.", ...
Key idea: The Euclidean algorithm computes gcds efficiently, and Bézout coefficients $u,v$ certify the result because every common divisor must divide $ua+vb=g$. (Here the result is $\boxed{2}$.)
math-013199
Number Theory: Modular Inverses — Extended Euclid
7
Track units/moduli carefully: Find the multiplicative inverse of $245$ modulo $268$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{268}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition fo...
[ { "method_name": "Uniqueness + Direct Check", "approach": "Solve by finding any $x$ that works and use uniqueness of inverses modulo $m$ to certify it.", "steps": [ "Step 1: Propose $x=233$ and compute $245x=57085$.", "Step 2: Reduce: $57085\\equiv 1\\pmod{268}$ (since $57084=57084$ is divis...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{233}$.\nMethod 1 constructs an inverse via Bézout, producing $x=233$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Sensitivity analysis: Extended Euclid is...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-013200
Number Theory: Congruences — Solving $ax\equiv 1$
7
Be explicit about assumptions: Find the multiplicative inverse of $7$ modulo $1482$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1482}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient condition f...
[ { "method_name": "Extended Euclidean Algorithm", "approach": "Use Bézout: find $u,v$ with $au+mv=1$, then $u$ is an inverse of $a$ modulo $m$.", "steps": [ "Step 1: Check $\\gcd(7,1482)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such that...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{847}$.\nMethod 1 constructs an inverse via Bézout, producing $x=847$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Extended Euclid is fast...
[ { "error_description": "Tried to invert even when $\\gcd(a,m)\\ne 1$.", "why_plausible": "The inverse notation $a^{-1}$ suggests it always exists.", "why_wrong": "If $d=\\gcd(a,m)>1$, then $ax$ is always divisible by $d$ modulo $m$, so it cannot be congruent to 1.", "which_method_catches_it": "Exten...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout. (Here the result is $\boxed{847}$.)