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math-011101
Number Theory: Divisibility — Linear Combinations
6
Explain what is being counted/optimized: (a) Compute $\gcd(1354,442)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1354+v\cdot 442=\gcd(1354,442)$. (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 $u=79$ and $v=-242$ with $u1354...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=79,v=-242$ satisfies $u1354+v442=2$, 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-011102
Number Theory: Modular Inverses — Extended Euclid
6
Work this out carefully: Find the multiplicative inverse of $62$ modulo $749$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{749}$). (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": "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 $x=447$ and compute $62x=27714$.", "Step 2: Reduce: $27714\\equiv 1\\pmod{749}$ (since $27713=27713$ is divisi...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{447}$.\nMethod 1 constructs an inverse via Bézout, producing $x=447$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness 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...
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 $\boxed{447}$.)
math-011103
Number Theory: Modular Inverses — Extended Euclid
6
Solve and include a self-check: Find the multiplicative inverse of $525$ modulo $1037$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1037}$). (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": "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 $x=399$ and compute $525x=209475$.", "Step 2: Reduce: $209475\\equiv 1\\pmod{1037}$ (since $209474=209474$ is ...
{ "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": "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...
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 $\boxed{399}$.)
math-011104
Computational Number Theory: Inverses and Certificates
6
Track units/moduli carefully: Find the multiplicative inverse of $483$ modulo $1966$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1966}$). (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 $x=289$ and compute $483x=139587$.", "Step 2: Reduce: $139587\\equiv 1\\pmod{1966}$ (since $139586=139586$ is ...
{ "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": "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...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011105
Number Theory: gcd — Back Substitution
6
Warm-up: (a) Compute $\gcd(638,1191)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 638+v\cdot 1191=\gcd(638,1191)$. (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": "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 $v=15$ with $u638+v...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-28,v=15$ satisfies $u638+v1191=1$, 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.", ...
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-011106
Number Theory: Modular Inverses — Extended Euclid
6
Track units/moduli carefully: Find the multiplicative inverse of $319$ modulo $326$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{326}$). (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 $x=93$ and compute $319x=29667$.", "Step 2: Reduce: $29667\\equiv 1\\pmod{326}$ (since $29666=29666$ is divisi...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{93}$.\nMethod 1 constructs an inverse via Bézout, producing $x=93$. 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...
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 $\boxed{93}$.)
math-011107
Number Theory: Modular Inverses — Extended Euclid
6
Challenge: Find the multiplicative inverse of $749$ 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 inverse to e...
[ { "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 $\\gcd(749,1195)=1$, 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: $\\boxed{844}$.\nMethod 1 constructs an inverse via Bézout, producing $x=844$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generali...
[ { "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 $\boxed{844}$.)
math-011108
Number Theory: Congruences — Solving $ax\equiv 1$
6
Provide both a computational and a conceptual explanation: Find the multiplicative inverse of $269$ modulo $432$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{432}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessar...
[ { "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 $\\gcd(269,432)=1$, 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: $\\boxed{53}$.\nMethod 1 constructs an inverse via Bézout, producing $x=53$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Ex...
[ { "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 $\boxed{53}$.)
math-011109
Number Theory: Divisibility — Linear Combinations
6
Checkpoint: (a) Compute $\gcd(1403,998)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1403+v\cdot 998=\gcd(1403,998)$. (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 ve...
[ { "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 $u=69$ and $v=-97$ with $u1403+...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=69,v=-97$ satisfies $u1403+v998=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the problem were perturbed: 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.", ...
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-011110
Number Theory: gcd — Back Substitution
6
Solve and sanity-check: (a) Compute $\gcd(1925,715)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1925+v\cdot 715=\gcd(1925,715)$. (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 $(1925,715)$ to compute $g=\\gcd(1925,715)$.", "Step 2: Record the remainder...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{55}$.\nThe Euclidean algorithm computes $g=55$. The Bézout certificate $u=3,v=-8$ satisfies $u1925+v715=55$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensitiv...
[ { "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 $\boxed{55}$.)
math-011111
Number Theory: Units mod m — Existence Condition
6
Solve with verification: Find the multiplicative inverse of $5$ modulo $1594$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1594}$). (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 $x=319$ and compute $5x=1595$.", "Step 2: Reduce: $1595\\equiv 1\\pmod{1594}$ (since $1594=1594$ is divisible ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{319}$.\nMethod 1 constructs an inverse via Bézout, producing $x=319$. 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...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011112
Number Theory: Congruences — Solving $ax\equiv 1$
6
Keep the final answer in boxed form: Find the multiplicative inverse of $965$ modulo $1457$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1457}$). (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": "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 $\\gcd(965,1457)=1$, 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: $\\boxed{690}$.\nMethod 1 constructs an inverse via Bézout, producing $x=690$. 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...
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 $\boxed{690}$.)
math-011113
Number Theory: Units mod m — Existence Condition
6
Proceed methodically: Find the multiplicative inverse of $709$ modulo $1192$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1192}$). (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": "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 $x=269$ and compute $709x=190721$.", "Step 2: Reduce: $190721\\equiv 1\\pmod{1192}$ (since $190720=190720$ is ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{269}$.\nMethod 1 constructs an inverse via Bézout, producing $x=269$. 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 $\boxed{269}$.)
math-011114
Number Theory: Units mod m — Existence Condition
6
Where appropriate, name the theorem you use: Find the multiplicative inverse of $45$ modulo $61$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{61}$). (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": "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 $\\gcd(45,61)=1$, 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: $\\boxed{19}$.\nMethod 1 constructs an inverse via Bézout, producing $x=19$. 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 $\boxed{19}$.)
math-011115
Number Theory: gcd — Euclidean Algorithm
6
Challenge: (a) Compute $\gcd(723,1458)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 723+v\cdot 1458=\gcd(723,1458)$. (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 $(723,1458)$ to compute $g=\\gcd(723,1458)$.", "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 $u=121,v=-60$ satisfies $u723+v1458=3$, 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.", ...
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-011116
Number Theory: Bézout Identity — Certificates
6
Use two approaches if possible: (a) Compute $\gcd(1329,1716)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1329+v\cdot 1716=\gcd(1329,1716)$. (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 $(1329,1716)$ to compute $g=\\gcd(1329,1716)$.", "Step 2: Record the remaind...
{ "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 $u=235,v=-182$ satisfies $u1329+v1716=3$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Genera...
[ { "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 $\boxed{3}$.)
math-011117
Number Theory: Modular Inverses — Extended Euclid
6
State any required conditions first: Find the multiplicative inverse of $610$ modulo $1301$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1301}$). (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 $x=787$ and compute $610x=480070$.", "Step 2: Reduce: $480070\\equiv 1\\pmod{1301}$ (since $480069=480069$ is ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{787}$.\nMethod 1 constructs an inverse via Bézout, producing $x=787$. 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...
Core principle: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011118
Number Theory: Units mod m — Existence Condition
6
Solve and sanity-check: Find the multiplicative inverse of $1609$ modulo $1987$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1987}$). (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": "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 $\\gcd(1609,1987)=1$, 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: $\\boxed{1393}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1393$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the...
[ { "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 $\boxed{1393}$.)
math-011119
Computational Number Theory: Inverses and Certificates
6
Be explicit about assumptions: Find the multiplicative inverse of $122$ modulo $387$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{387}$). (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 $x=92$ and compute $122x=11224$.", "Step 2: Reduce: $11224\\equiv 1\\pmod{387}$ (since $11223=11223$ is divisi...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{92}$.\nMethod 1 constructs an inverse via Bézout, producing $x=92$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the pro...
[ { "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 $\boxed{92}$.)
math-011120
Number Theory: Bézout Identity — Certificates
6
Solve and then verify: (a) Compute $\gcd(126,103)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 126+v\cdot 103=\gcd(126,103)$. (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 ...
[ { "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 $u=9$ and $v=-11$ with $u126+v1...
{ "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 $u=9,v=-11$ satisfies $u126+v103=1$, 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.", ...
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-011121
Number Theory: gcd — Back Substitution
6
Where appropriate, name the theorem you use: (a) Compute $\gcd(535,559)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 535+v\cdot 559=\gcd(535,559)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitut...
[ { "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 $(535,559)$ to compute $g=\\gcd(535,559)$.", "Step 2: Record the remainder e...
{ "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 $u=163,v=-156$ satisfies $u535+v559=1$, 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-011122
Number Theory: Modular Inverses — Extended Euclid
6
Explain each transformation: Find the multiplicative inverse of $865$ modulo $1421$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1421}$). (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 $\\gcd(865,1421)=1$, 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: $\\boxed{23}$.\nMethod 1 constructs an inverse via Bézout, producing $x=23$. 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. (Here the result is $\boxed{23}$.)
math-011123
Computational Number Theory: Extended Euclid
6
Work this out carefully: (a) Compute $\gcd(1939,1618)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1939+v\cdot 1618=\gcd(1939,1618)$. (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 $(1939,1618)$ to compute $g=\\gcd(1939,1618)$.", "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 $u=373,v=-447$ satisfies $u1939+v1618=1$, 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 $ua+vb=g$.
math-011124
Number Theory: Bézout Identity — Certificates
6
Find the exact value: (a) Compute $\gcd(791,410)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 791+v\cdot 410=\gcd(791,410)$. (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 b...
[ { "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 $u=-99$ and $v=191$ with $u791+...
{ "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 $u=-99,v=191$ satisfies $u791+v410=1$, 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-011125
Number Theory: Divisibility — Linear Combinations
6
Track units/moduli carefully: (a) Compute $\gcd(1461,744)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1461+v\cdot 744=\gcd(1461,744)$. (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 $u=55$ and $v=-108$ with $u1461...
{ "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 $u=55,v=-108$ satisfies $u1461+v744=3$, 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-011126
Number Theory: Bézout Identity — Certificates
6
Show all reasoning: (a) Compute $\gcd(315,1191)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 315+v\cdot 1191=\gcd(315,1191)$. (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 ...
[ { "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 $(315,1191)$ to compute $g=\\gcd(315,1191)$.", "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 $u=121,v=-32$ satisfies $u315+v1191=3$, 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.", ...
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-011127
Number Theory: gcd — Back Substitution
6
Explain what is being counted/optimized: (a) Compute $\gcd(314,805)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 314+v\cdot 805=\gcd(314,805)$. (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 $(314,805)$ to compute $g=\\gcd(314,805)$.", "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 $u=-141,v=55$ satisfies $u314+v805=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness note: Euclid scales 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 $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-011128
Computational Number Theory: Extended Euclid
6
Complete the analysis: (a) Compute $\gcd(602,131)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 602+v\cdot 131=\gcd(602,131)$. (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 ...
[ { "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 $u=42$ and $v=-193$ with $u602+...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=42,v=-193$ satisfies $u602+v131=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: 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-011129
Number Theory: Divisibility — Linear Combinations
6
Answer using clear logical steps: (a) Compute $\gcd(538,641)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 538+v\cdot 641=\gcd(538,641)$. (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 $(538,641)$ to compute $g=\\gcd(538,641)$.", "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 $u=56,v=-47$ satisfies $u538+v641=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Generality note: 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 $\boxed{1}$.)
math-011130
Number Theory: Congruences — Solving $ax\equiv 1$
6
Challenge: Find the multiplicative inverse of $607$ modulo $1023$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1023}$). (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 e...
[ { "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 $x=391$ and compute $607x=237337$.", "Step 2: Reduce: $237337\\equiv 1\\pmod{1023}$ (since $237336=237336$ is ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{391}$.\nMethod 1 constructs an inverse via Bézout, producing $x=391$. 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...
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 $\boxed{391}$.)
math-011131
Number Theory: Divisibility — Linear Combinations
6
Try to avoid pattern-matching; explain why: (a) Compute $\gcd(494,1867)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 494+v\cdot 1867=\gcd(494,1867)$. (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 $u=-805$ and $v=213$ with $u494...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-805,v=213$ satisfies $u494+v1867=1$, 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 $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-011132
Number Theory: Modular Inverses — Extended Euclid
6
Solve with verification: Find the multiplicative inverse of $1180$ modulo $1557$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1557}$). (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 $\\gcd(1180,1557)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such t...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1144}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1144$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness 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 $\boxed{1144}$.)
math-011133
Number Theory: gcd — Euclidean Algorithm
6
Exercise: (a) Compute $\gcd(1788,1562)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1788+v\cdot 1562=\gcd(1788,1562)$. (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 $(1788,1562)$ to compute $g=\\gcd(1788,1562)$.", "Step 2: Record the remaind...
{ "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 $u=235,v=-269$ satisfies $u1788+v1562=2$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robust...
[ { "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 $\boxed{2}$.)
math-011134
Number Theory: Modular Inverses — Extended Euclid
6
Carefully track domains: Find the multiplicative inverse of $403$ modulo $413$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{413}$). (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 $x=289$ and compute $403x=116467$.", "Step 2: Reduce: $116467\\equiv 1\\pmod{413}$ (since $116466=116466$ is d...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. 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": "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...
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 $\boxed{289}$.)
math-011135
Computational Number Theory: Inverses and Certificates
6
Give a theorem-based solution: Find the multiplicative inverse of $221$ modulo $330$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{330}$). (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 $\\gcd(221,330)=1$, 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: $\\boxed{221}$.\nMethod 1 constructs an inverse via Bézout, producing $x=221$. 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...
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 $\boxed{221}$.)
math-011136
Number Theory: Congruences — Solving $ax\equiv 1$
6
Solve (and briefly cross-validate): Find the multiplicative inverse of $732$ modulo $887$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{887}$). (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 $x=103$ and compute $732x=75396$.", "Step 2: Reduce: $75396\\equiv 1\\pmod{887}$ (since $75395=75395$ is divis...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{103}$.\nMethod 1 constructs an inverse via Bézout, producing $x=103$. 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.
math-011137
Number Theory: Bézout Identity — Certificates
6
Work this out carefully: (a) Compute $\gcd(377,275)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 377+v\cdot 275=\gcd(377,275)$. (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": "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 $u=-62$ and $v=85$ with $u377+v...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=-62,v=85$ satisfies $u377+v275=1$, 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.", ...
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-011138
Number Theory: gcd — Back Substitution
6
Provide both a computational and a conceptual explanation: (a) Compute $\gcd(538,477)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 538+v\cdot 477=\gcd(538,477)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear back...
[ { "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 $(538,477)$ to compute $g=\\gcd(538,477)$.", "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 $u=-86,v=97$ satisfies $u538+v477=1$, 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 $ua+vb=g$. (Here the result is $\boxed{1}$.)
math-011139
Number Theory: Units mod m — Existence Condition
6
Give a theorem-based solution: Find the multiplicative inverse of $49$ modulo $1343$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1343}$). (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 $\\gcd(49,1343)=1$, 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: $\\boxed{603}$.\nMethod 1 constructs an inverse via Bézout, producing $x=603$. 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...
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 $\boxed{603}$.)
math-011140
Computational Number Theory: Extended Euclid
6
Warm-up: (a) Compute $\gcd(1631,1593)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1631+v\cdot 1593=\gcd(1631,1593)$. (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 ve...
[ { "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 $u=545$ and $v=-558$ with $u163...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=545,v=-558$ satisfies $u1631+v1593=1$, 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.", ...
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-011141
Number Theory: gcd — Back Substitution
6
Answer with a short justification: (a) Compute $\gcd(1303,1682)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1303+v\cdot 1682=\gcd(1303,1682)$. (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 $(1303,1682)$ to compute $g=\\gcd(1303,1682)$.", "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 $u=-537,v=416$ satisfies $u1303+v1682=1$, 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.", ...
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-011142
Number Theory: gcd — Euclidean Algorithm
6
Exercise: (a) Compute $\gcd(1743,823)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1743+v\cdot 823=\gcd(1743,823)$. (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": "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 $u=280$ and $v=-593$ with $u174...
{ "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 $u=280,v=-593$ satisfies $u1743+v823=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensiti...
[ { "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-011143
Computational Number Theory: Inverses and Certificates
6
Warm-up: Find the multiplicative inverse of $1054$ modulo $1531$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1531}$). (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": "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 $x=1332$ and compute $1054x=1403928$.", "Step 2: Reduce: $1403928\\equiv 1\\pmod{1531}$ (since $1403927=140392...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1332}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1332$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "If the problem were perturbed: Extende...
[ { "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 $\boxed{1332}$.)
math-011144
Number Theory: Congruences — Solving $ax\equiv 1$
6
Task: Find the multiplicative inverse of $293$ modulo $975$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{975}$). (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 $x=782$ and compute $293x=229126$.", "Step 2: Reduce: $229126\\equiv 1\\pmod{975}$ (since $229125=229125$ is d...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{782}$.\nMethod 1 constructs an inverse via Bézout, producing $x=782$. 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. (Here the result is $\boxed{782}$.)
math-011145
Number Theory: Units mod m — Existence Condition
6
Give a theorem-based solution: Find the multiplicative inverse of $329$ modulo $428$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{428}$). (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 $x=281$ and compute $329x=92449$.", "Step 2: Reduce: $92449\\equiv 1\\pmod{428}$ (since $92448=92448$ is divis...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{281}$.\nMethod 1 constructs an inverse via Bézout, producing $x=281$. 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...
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 $\boxed{281}$.)
math-011146
Number Theory: Units mod m — Existence Condition
6
Give a fully justified solution: Find the multiplicative inverse of $454$ modulo $1359$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1359}$). (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 $\\gcd(454,1359)=1$, 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: $\\boxed{907}$.\nMethod 1 constructs an inverse via Bézout, producing $x=907$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generali...
[ { "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 $\boxed{907}$.)
math-011147
Number Theory: Congruences — Solving $ax\equiv 1$
6
Give reasoning, not just computation: Find the multiplicative inverse of $1095$ modulo $1357$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1357}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient c...
[ { "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 $x=1155$ and compute $1095x=1264725$.", "Step 2: Reduce: $1264725\\equiv 1\\pmod{1357}$ (since $1264724=126472...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{1155}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1155$. 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...
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 $\boxed{1155}$.)
math-011148
Number Theory: Units mod m — Existence Condition
6
Exercise: Find the multiplicative inverse of $725$ modulo $1613$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1613}$). (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 $\\gcd(725,1613)=1$, 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: $\\boxed{663}$.\nMethod 1 constructs an inverse via Bézout, producing $x=663$. 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 $\boxed{663}$.)
math-011149
Number Theory: gcd — Back Substitution
6
Give reasoning, not just computation: (a) Compute $\gcd(613,1323)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 613+v\cdot 1323=\gcd(613,1323)$. (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 $(613,1323)$ to compute $g=\\gcd(613,1323)$.", "Step 2: Record the remainder...
{ "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 $u=-341,v=158$ satisfies $u613+v1323=1$, 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.", ...
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-011150
Computational Number Theory: Inverses and Certificates
6
Work carefully and justify each inference: Find the multiplicative inverse of $1187$ modulo $1293$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1293}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and suffici...
[ { "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 $\\gcd(1187,1293)=1$, so an inverse exists.", "Step 2: Use the extended Euclidean algorithm to find integers $u,v$ such t...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{1232}$.\nMethod 1 constructs an inverse via Bézout, producing $x=1232$. 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...
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 $\boxed{1232}$.)
math-011151
Computational Number Theory: Inverses and Certificates
6
Provide both a computational and a conceptual explanation: Find the multiplicative inverse of $1163$ modulo $1419$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1419}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the neces...
[ { "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 $x=194$ and compute $1163x=225622$.", "Step 2: Reduce: $225622\\equiv 1\\pmod{1419}$ (since $225621=225621$ is...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{194}$.\nMethod 1 constructs an inverse via Bézout, producing $x=194$. 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...
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 $\boxed{194}$.)
math-011152
Number Theory: Modular Inverses — Extended Euclid
6
Prompt: Find the multiplicative inverse of $837$ modulo $1141$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1141}$). (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 $x=289$ and compute $837x=241893$.", "Step 2: Reduce: $241893\\equiv 1\\pmod{1141}$ (since $241892=241892$ is ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. 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": "Robustness 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.
math-011153
Computational Number Theory: Inverses and Certificates
6
Give a theorem-based solution: Find the multiplicative inverse of $377$ modulo $1462$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1462}$). (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 $\\gcd(377,1462)=1$, 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: $\\boxed{159}$.\nMethod 1 constructs an inverse via Bézout, producing $x=159$. 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...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011154
Number Theory: Units mod m — Existence Condition
6
Do not skip justification steps: Find the multiplicative inverse of $346$ modulo $755$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{755}$). (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 $\\gcd(346,755)=1$, 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: $\\boxed{731}$.\nMethod 1 constructs an inverse via Bézout, producing $x=731$. 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 $\boxed{731}$.)
math-011155
Number Theory: gcd — Back Substitution
6
Problem: (a) Compute $\gcd(1317,706)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1317+v\cdot 706=\gcd(1317,706)$. (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 $(1317,706)$ to compute $g=\\gcd(1317,706)$.", "Step 2: Record the remainder...
{ "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 $u=-327,v=610$ satisfies $u1317+v706=1$, 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.", ...
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-011156
Number Theory: gcd — Back Substitution
6
Do not skip justification steps: (a) Compute $\gcd(1789,1201)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1789+v\cdot 1201=\gcd(1789,1201)$. (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 $u=96$ and $v=-143$ with $u1789...
{ "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 $u=96,v=-143$ satisfies $u1789+v1201=1$, 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-011157
Number Theory: gcd — Back Substitution
6
State any required conditions first: (a) Compute $\gcd(474,947)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 474+v\cdot 947=\gcd(474,947)$. (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 $(474,947)$ to compute $g=\\gcd(474,947)$.", "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 $u=2,v=-1$ satisfies $u474+v947=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "If the probl...
[ { "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-011158
Number Theory: Congruences — Solving $ax\equiv 1$
6
Task: Find the multiplicative inverse of $184$ modulo $361$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{361}$). (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 $x=155$ and compute $184x=28520$.", "Step 2: Reduce: $28520\\equiv 1\\pmod{361}$ (since $28519=28519$ is divis...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{155}$.\nMethod 1 constructs an inverse via Bézout, producing $x=155$. 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...
Takeaway: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011159
Number Theory: Modular Inverses — Extended Euclid
6
Keep the final answer in boxed form: Find the multiplicative inverse of $553$ modulo $698$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{698}$). (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": "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 $x=491$ and compute $553x=271523$.", "Step 2: Reduce: $271523\\equiv 1\\pmod{698}$ (since $271522=271522$ is d...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{491}$.\nMethod 1 constructs an inverse via Bézout, producing $x=491$. 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...
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 $\boxed{491}$.)
math-011160
Number Theory: Units mod m — Existence Condition
6
Prompt: Find the multiplicative inverse of $234$ modulo $863$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{863}$). (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 $\\gcd(234,863)=1$, 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: $\\boxed{402}$.\nMethod 1 constructs an inverse via Bézout, producing $x=402$. 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...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011161
Number Theory: Modular Inverses — Extended Euclid
6
Explain each transformation: Find the multiplicative inverse of $792$ modulo $1367$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1367}$). (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 $x=126$ and compute $792x=99792$.", "Step 2: Reduce: $99792\\equiv 1\\pmod{1367}$ (since $99791=99791$ is divi...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{126}$.\nMethod 1 constructs an inverse via Bézout, producing $x=126$. 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.
math-011162
Number Theory: Units mod m — Existence Condition
6
Carefully track domains: Find the multiplicative inverse of $827$ modulo $1446$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1446}$). (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": "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 $\\gcd(827,1446)=1$, 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: $\\boxed{869}$.\nMethod 1 constructs an inverse via Bézout, producing $x=869$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generali...
[ { "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 $\boxed{869}$.)
math-011163
Number Theory: Congruences — Solving $ax\equiv 1$
6
Complete the analysis: Find the multiplicative inverse of $245$ 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 in...
[ { "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 $x=346$ and compute $245x=84770$.", "Step 2: Reduce: $84770\\equiv 1\\pmod{823}$ (since $84769=84769$ is divis...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{346}$.\nMethod 1 constructs an inverse via Bézout, producing $x=346$. 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...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011164
Number Theory: gcd — Euclidean Algorithm
6
Try to avoid pattern-matching; explain why: (a) Compute $\gcd(227,1458)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 227+v\cdot 1458=\gcd(227,1458)$. (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 $u=167$ and $v=-26$ with $u227+...
{ "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 $u=167,v=-26$ satisfies $u227+v1458=1$, 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.", ...
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-011165
Computational Number Theory: Inverses and Certificates
6
Track units/moduli carefully: Find the multiplicative inverse of $598$ modulo $651$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{651}$). (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 $\\gcd(598,651)=1$, 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: $\\boxed{565}$.\nMethod 1 constructs an inverse via Bézout, producing $x=565$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generali...
[ { "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 $\boxed{565}$.)
math-011166
Number Theory: Units mod m — Existence Condition
6
Where appropriate, name the theorem you use: Find the multiplicative inverse of $43$ modulo $584$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{584}$). (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 $x=163$ and compute $43x=7009$.", "Step 2: Reduce: $7009\\equiv 1\\pmod{584}$ (since $7008=7008$ is divisible ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{163}$.\nMethod 1 constructs an inverse via Bézout, producing $x=163$. 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...
Key idea: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011167
Number Theory: Units mod m — Existence Condition
6
Task: Find the multiplicative inverse of $73$ 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 exist. I...
[ { "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 $x=409$ and compute $73x=29857$.", "Step 2: Reduce: $29857\\equiv 1\\pmod{933}$ (since $29856=29856$ is divisi...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. 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": "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...
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 $\boxed{409}$.)
math-011168
Number Theory: Modular Inverses — Extended Euclid
6
Solve (and briefly cross-validate): Find the multiplicative inverse of $73$ modulo $224$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{224}$). (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 $x=89$ and compute $73x=6497$.", "Step 2: Reduce: $6497\\equiv 1\\pmod{224}$ (since $6496=6496$ is divisible b...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{89}$.\nMethod 1 constructs an inverse via Bézout, producing $x=89$. 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...
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 $\boxed{89}$.)
math-011169
Number Theory: Modular Inverses — Extended Euclid
6
Solve and include a self-check: Find the multiplicative inverse of $869$ modulo $1028$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1028}$). (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": "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 $x=653$ and compute $869x=567457$.", "Step 2: Reduce: $567457\\equiv 1\\pmod{1028}$ (since $567456=567456$ is ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{653}$.\nMethod 1 constructs an inverse via Bézout, producing $x=653$. 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 $\boxed{653}$.)
math-011170
Number Theory: Divisibility — Linear Combinations
6
Derive the result step-by-step: (a) Compute $\gcd(764,1057)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 764+v\cdot 1057=\gcd(764,1057)$. (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 $u=386$ and $v=-279$ with $u764...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{1}$.\nThe Euclidean algorithm computes $g=1$. The Bézout certificate $u=386,v=-279$ satisfies $u764+v1057=1$, 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-011171
Computational Number Theory: Inverses and Certificates
6
Give an answer and a quick verification: Find the multiplicative inverse of $485$ modulo $569$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{569}$). (a) Solve using the extended Euclidean algorithm. (b) Give an independent verification by checking the congruence. (c) Briefly state the necessary and sufficient c...
[ { "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 $\\gcd(485,569)=1$, 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: $\\boxed{359}$.\nMethod 1 constructs an inverse via Bézout, producing $x=359$. 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.
math-011172
Number Theory: Divisibility — Linear Combinations
6
Write the solution set clearly: (a) Compute $\gcd(487,1481)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 487+v\cdot 1481=\gcd(487,1481)$. (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 $u=222$ and $v=-73$ with $u487+...
{ "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 $u=222,v=-73$ satisfies $u487+v1481=1$, 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.", ...
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-011173
Number Theory: gcd — Euclidean Algorithm
6
Give a fully justified solution: (a) Compute $\gcd(1686,1465)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1686+v\cdot 1465=\gcd(1686,1465)$. (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 $u=411$ and $v=-473$ with $u168...
{ "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 $u=411,v=-473$ satisfies $u1686+v1465=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Genera...
[ { "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-011174
Number Theory: Congruences — Solving $ax\equiv 1$
6
Give an answer and a quick verification: Find the multiplicative inverse of $3$ modulo $92$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{92}$). (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 $\\gcd(3,92)=1$, 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: $\\boxed{31}$.\nMethod 1 constructs an inverse via Bézout, producing $x=31$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness note: Ex...
[ { "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 $\boxed{31}$.)
math-011175
Number Theory: Modular Inverses — Extended Euclid
6
Track quantifiers carefully: Find the multiplicative inverse of $510$ modulo $1199$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1199}$). (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 $x=355$ and compute $510x=181050$.", "Step 2: Reduce: $181050\\equiv 1\\pmod{1199}$ (since $181049=181049$ is ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{355}$.\nMethod 1 constructs an inverse via Bézout, producing $x=355$. 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 $\boxed{355}$.)
math-011176
Number Theory: Divisibility — Linear Combinations
6
Work this out carefully: (a) Compute $\gcd(1303,628)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1303+v\cdot 628=\gcd(1303,628)$. (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 $u=147$ and $v=-305$ with $u130...
{ "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 $u=147,v=-305$ satisfies $u1303+v628=1$, 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-011177
Number Theory: Congruences — Solving $ax\equiv 1$
6
Solve and justify each step: Find the multiplicative inverse of $571$ modulo $1532$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1532}$). (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 $x=711$ and compute $571x=405981$.", "Step 2: Reduce: $405981\\equiv 1\\pmod{1532}$ (since $405980=405980$ is ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{711}$.\nMethod 1 constructs an inverse via Bézout, producing $x=711$. 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 $\boxed{711}$.)
math-011178
Number Theory: Modular Inverses — Extended Euclid
6
Give reasoning, not just computation: Find the multiplicative inverse of $797$ modulo $1574$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1574}$). (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 $x=551$ and compute $797x=439147$.", "Step 2: Reduce: $439147\\equiv 1\\pmod{1574}$ (since $439146=439146$ is ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{551}$.\nMethod 1 constructs an inverse via Bézout, producing $x=551$. 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. (Here the result is $\boxed{551}$.)
math-011179
Number Theory: Units mod m — Existence Condition
6
Solve with verification: Find the multiplicative inverse of $198$ modulo $1019$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1019}$). (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": "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 $\\gcd(198,1019)=1$, 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: $\\boxed{808}$.\nMethod 1 constructs an inverse via Bézout, producing $x=808$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generali...
[ { "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-011180
Number Theory: Units mod m — Existence Condition
6
Warm-up: Find the multiplicative inverse of $17$ modulo $593$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{593}$). (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 $\\gcd(17,593)=1$, 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: $\\boxed{314}$.\nMethod 1 constructs an inverse via Bézout, producing $x=314$. 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...
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 $\boxed{314}$.)
math-011181
Number Theory: Bézout Identity — Certificates
6
Determine the requested value: (a) Compute $\gcd(639,1802)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 639+v\cdot 1802=\gcd(639,1802)$. (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 $(639,1802)$ to compute $g=\\gcd(639,1802)$.", "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 $u=-141,v=50$ satisfies $u639+v1802=1$, 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-011182
Number Theory: Units mod m — Existence Condition
6
Indicate where a theorem is used: Find the multiplicative inverse of $793$ modulo $1073$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1073}$). (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": "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 $\\gcd(793,1073)=1$, 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: $\\boxed{525}$.\nMethod 1 constructs an inverse via Bézout, producing $x=525$. 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 $\boxed{525}$.)
math-011183
Number Theory: Divisibility — Linear Combinations
6
Track units/moduli carefully: (a) Compute $\gcd(1600,1336)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1600+v\cdot 1336=\gcd(1600,1336)$. (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 $(1600,1336)$ to compute $g=\\gcd(1600,1336)$.", "Step 2: Record the remaind...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{8}$.\nThe Euclidean algorithm computes $g=8$. The Bézout certificate $u=81,v=-97$ satisfies $u1600+v1336=8$, 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 $ua+vb=g$.
math-011184
Computational Number Theory: Extended Euclid
6
Explain why your operations are valid: (a) Compute $\gcd(1933,1609)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1933+v\cdot 1609=\gcd(1933,1609)$. (c) Briefly explain why your coefficients certify the gcd. You must show the Euclidean algorithm remainder steps or a clear backward-substitut...
[ { "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 $(1933,1609)$ to compute $g=\\gcd(1933,1609)$.", "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 $u=293,v=-352$ satisfies $u1933+v1609=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness 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.", ...
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-011185
Number Theory: Units mod m — Existence Condition
6
Work this out carefully: Find the multiplicative inverse of $385$ modulo $818$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{818}$). (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 $\\gcd(385,818)=1$, 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: $\\boxed{17}$.\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": "Sensitivit...
[ { "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-011186
Number Theory: gcd — Back Substitution
6
Try to avoid pattern-matching; explain why: (a) Compute $\gcd(988,842)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 988+v\cdot 842=\gcd(988,842)$. (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 $u=-173$ and $v=203$ with $u988...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{2}$.\nThe Euclidean algorithm computes $g=2$. The Bézout certificate $u=-173,v=203$ satisfies $u988+v842=2$, 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.", ...
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-011187
Number Theory: Congruences — Solving $ax\equiv 1$
6
Derive the result step-by-step: Find the multiplicative inverse of $881$ modulo $1014$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1014}$). (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": "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 $x=953$ and compute $881x=839593$.", "Step 2: Reduce: $839593\\equiv 1\\pmod{1014}$ (since $839592=839592$ is ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{953}$.\nMethod 1 constructs an inverse via Bézout, producing $x=953$. 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.
math-011188
Number Theory: Bézout Identity — Certificates
6
Track quantifiers carefully: (a) Compute $\gcd(1941,1329)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1941+v\cdot 1329=\gcd(1941,1329)$. (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 $(1941,1329)$ to compute $g=\\gcd(1941,1329)$.", "Step 2: Record the remaind...
{ "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 $u=-76,v=111$ satisfies $u1941+v1329=3$, 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.", ...
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-011189
Number Theory: Divisibility — Linear Combinations
6
Solve and sanity-check: (a) Compute $\gcd(337,1139)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 337+v\cdot 1139=\gcd(337,1139)$. (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 $(337,1139)$ to compute $g=\\gcd(337,1139)$.", "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 $u=436,v=-129$ satisfies $u337+v1139=1$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Sensiti...
[ { "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-011190
Number Theory: gcd — Euclidean Algorithm
6
Answer with a short justification: (a) Compute $\gcd(90,900)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 90+v\cdot 900=\gcd(90,900)$. (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 $(90,900)$ to compute $g=\\gcd(90,900)$.", "Step 2: Record the remainder equ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{90}$.\nThe Euclidean algorithm computes $g=90$. The Bézout certificate $u=1,v=0$ satisfies $u90+v900=90$, and divisibility shows no larger common divisor can exist.", "robustness_analysis": "Robustness note: Euclid scal...
[ { "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-011191
Number Theory: Units mod m — Existence Condition
6
Work carefully and justify each inference: Find the multiplicative inverse of $133$ modulo $645$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{645}$). (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 $x=97$ and compute $133x=12901$.", "Step 2: Reduce: $12901\\equiv 1\\pmod{645}$ (since $12900=12900$ is divisi...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{97}$.\nMethod 1 constructs an inverse via Bézout, producing $x=97$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Generality note: Ex...
[ { "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 $\boxed{97}$.)
math-011192
Computational Number Theory: Inverses and Certificates
6
Question: Find the multiplicative inverse of $59$ modulo $303$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{303}$). (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 $\\gcd(59,303)=1$, 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: $\\boxed{113}$.\nMethod 1 constructs an inverse via Bézout, producing $x=113$. 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...
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 $\boxed{113}$.)
math-011193
Number Theory: gcd — Back Substitution
6
Complete the analysis: (a) Compute $\gcd(1787,1492)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 1787+v\cdot 1492=\gcd(1787,1492)$. (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": "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 $(1787,1492)$ to compute $g=\\gcd(1787,1492)$.", "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 $u=263,v=-315$ satisfies $u1787+v1492=1$, 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.", ...
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-011194
Number Theory: Congruences — Solving $ax\equiv 1$
6
Give reasoning, not just computation: Find the multiplicative inverse of $46$ modulo $201$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{201}$). (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": "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 $x=118$ and compute $46x=5428$.", "Step 2: Reduce: $5428\\equiv 1\\pmod{201}$ (since $5427=5427$ is divisible ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{118}$.\nMethod 1 constructs an inverse via Bézout, producing $x=118$. 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 $\boxed{118}$.)
math-011195
Number Theory: Units mod m — Existence Condition
6
Solve and justify each step: Find the multiplicative inverse of $881$ modulo $1153$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1153}$). (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 $x=479$ and compute $881x=421999$.", "Step 2: Reduce: $421999\\equiv 1\\pmod{1153}$ (since $421998=421998$ is ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{479}$.\nMethod 1 constructs an inverse via Bézout, producing $x=479$. 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...
Remember: A modular inverse exists iff $\gcd(a,m)=1$. Extended Euclid constructs it and also provides a proof certificate via Bézout.
math-011196
Number Theory: Modular Inverses — Extended Euclid
6
State any required conditions first: Find the multiplicative inverse of $655$ modulo $1177$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1177}$). (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 $x=354$ and compute $655x=231870$.", "Step 2: Reduce: $231870\\equiv 1\\pmod{1177}$ (since $231869=231869$ is ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{354}$.\nMethod 1 constructs an inverse via Bézout, producing $x=354$. Method 2 verifies $ax\\equiv 1$ directly and uses uniqueness, so both necessarily agree.", "robustness_analysis": "Robustness 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 $\boxed{354}$.)
math-011197
Number Theory: Congruences — Solving $ax\equiv 1$
6
Provide a rigorous solution: Find the multiplicative inverse of $765$ modulo $796$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{796}$). (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 $\\gcd(765,796)=1$, 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": "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...
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 $\boxed{77}$.)
math-011198
Number Theory: Divisibility — Linear Combinations
6
Where appropriate, name the theorem you use: (a) Compute $\gcd(155,1795)$ using the Euclidean algorithm. (b) Find integers $u,v$ such that $u\cdot 155+v\cdot 1795=\gcd(155,1795)$. (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 $u=139$ and $v=-12$ with $u155+...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{5}$.\nThe Euclidean algorithm computes $g=5$. The Bézout certificate $u=139,v=-12$ satisfies $u155+v1795=5$, 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-011199
Number Theory: Units mod m — Existence Condition
6
Give a theorem-based solution: Find the multiplicative inverse of $817$ modulo $1640$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{1640}$). (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 $x=273$ and compute $817x=223041$.", "Step 2: Reduce: $223041\\equiv 1\\pmod{1640}$ (since $223040=223040$ is ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{273}$.\nMethod 1 constructs an inverse via Bézout, producing $x=273$. 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...
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 $\boxed{273}$.)
math-011200
Computational Number Theory: Inverses and Certificates
6
Give reasoning, not just computation: Find the multiplicative inverse of $251$ modulo $603$ (i.e., find an integer $x$ such that $ax\equiv 1\pmod{603}$). (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 $\\gcd(251,603)=1$, 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: $\\boxed{197}$.\nMethod 1 constructs an inverse via Bézout, producing $x=197$. 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...
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 $\boxed{197}$.)