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rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
we can evaluate what 8 plus 3 is . 8 plus 3 is 11 . so if we do that -- let me do that in this direction .
so.. what would 6 ( g+3 ) be ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
so what 's 8 added to itself four times ? that is 4 times 8 . so this is 4 times 8 , and what is this over here in the orange ?
what is 4 ( 6-8*9+5 ) +-5 ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
so what 's 8 added to itself four times ? that is 4 times 8 . so this is 4 times 8 , and what is this over here in the orange ?
i cut off a piece of length 4 '' what is the area of the remaining piece ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
8 plus 3 is 11 , and then this is going to be equal to -- well , 4 times 11 is just 44 , so you can evaluate it that way . but they want us to use the distributive law of multiplication . we did not use the distributive law just now . we just evaluated the expression .
when will you ever need to use expressions in life ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression .
what is the difference between the law of multiplication and the addition rule ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
so we only use the distribution property when we have things in brackets ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression .
when do i know to keep the brackets and when not too ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression .
when do we decide to put/or have to put parenthesis and when not to ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
what is and how do you do distributive property of division ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
what is a distributed property/ law ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
so , how would you answer a problem say its like 3 loaves of bread for $ 1.99 how would you awnser that with the distributive property ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
8 plus 3 is 11 , and then this is going to be equal to -- well , 4 times 11 is just 44 , so you can evaluate it that way . but they want us to use the distributive law of multiplication . we did not use the distributive law just now . we just evaluated the expression .
does sal use the distributive law 7 ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
a lot of people 's first instinct is just to multiply the 4 times the 8 , but no ! you have to distribute the 4 . you have to multiply it times the 8 and times the 3 .
so what exactly does distribute mean ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
how would the distributive property work if the problem is ( 3-6 ) ^2 ( where the two is to the second power of ( 3-6 ) ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
what is the commutative property ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
can any one tell me how to apply the distributive property to everyday life or who uses this type of math ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
so you can imagine this is what we have inside of the parentheses . we have 8 circles plus 3 circles . now , when we 're multiplying this whole thing , this whole thing times 4 , what does that mean ?
why did sal say to add all the blue and red circles up when you could multiply them ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
how do you use the distributive property using variables and numbers ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
this is the distributive property in action right here . distributive property in action . and then when you evaluate it -- and i 'm going to show you in kind of a visual way why this works .
why is the distributive property so useful ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
one , two , three . so you can imagine this is what we have inside of the parentheses . we have 8 circles plus 3 circles .
if you had an negative number would the negative be distributed to the equation inside the bracket or not ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
and then we 're going to add to that three of something , of maybe the same thing . one , two , three . so you can imagine this is what we have inside of the parentheses .
also if you had two numbers in front of the bracket and the first was a positive and the second was an negative would both numbers be distributed or not ?
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression . so let 's just try to solve this or evaluate this expression , then we 'll talk a little bit about the distributive law of multiplication over addition ...
rewrite the expression 4 times , and then in parentheses we have 8 plus 3 , using the distributive law of multiplication over addition . then simplify the expression .
does butt chicken tastes good ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level .
what is the difference between a `` estimated '' number and a `` projected '' number ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
so the cost of funding retirements for people who have already done service for the state but are n't in service to the state right now is going to pass up -- and this is happening very soon -- is going to pass up actual spending on a state-wide basis on education . and at the state level , education is a major , major...
i 'm just thinking how bad this will be in 30 years from now when i retire , will the state cut/will i lose my promised pension altogether or , as selfish as it sounds , will the state still pay up at the cost of cutting major funding for other things like they have been doing ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
and in order to meet those obligations , those promised obligations , they 're going to have to dig into money that was being spent other places , that going in the past when they were underfunding the pension , they were able to fund other things nicely , but not fund the pension and kind of kick the can down the road...
do n't you think a numbers guy should shop around for a better rate ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
and there 's a lot of things that go into the total liabilities , the same things that we talked about in the last video . there are things like return on investment . if you are in a low interest rate environment , like we are now -- for example , my money in my savings account , i think , is getting like 0.4 % intere...
does illinois report its funding ratio assuming the more reasonable rates of return expressed in the previous video and if so , what is its funded status at those rates of return ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
so it 's 138 billion . this is for one state . and 85 or 86 billion of that is unfunded , that they have to figure out some way to get the money because the right amount of money was not being set aside .
why should the state fund pensions ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
they 've set aside 83 % of the right amount of money to fund their pension obligations , not 100 % . it is underfunded , but it 's not crazy . california , pretty high , 78 % .
is n't it the company 's fault for having underfunded pensions ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
but one of these states is probably jumping out at you , probably because it has been shaded in red . and that is the state of illinois , and illinois is in trouble because it 's only funded 45 % of its pension obligations . and illinois really jumps out because it 's in red , but there 's a lot of states that are pret...
can illinois get out of dept with out raising taxes ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
but they are also sometimes negotiated . and sometimes , and especially in the case of illinois , they 've grown faster than the rate of inflation . and so you have these liabilities , and you see that they 're getting less and less well funded .
when the inflation rate start to increase past 3 percent , would the cola automatically increase to match the new higher inflation rate ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
so it 's 138 billion . this is for one state . and 85 or 86 billion of that is unfunded , that they have to figure out some way to get the money because the right amount of money was not being set aside .
my question is , are any of the state pension funds managed by our `` too big to fail '' brokerage firms , like j.p. morgan chase ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
but now that the can ca n't be kicked any further , it 's going to have to go the other way around . you 're going to have to take money from other things to fund your pensions . and to make it clear , let 's focus on the state of illinois .
if we forced them all to take bailout money , why ca n't we ask them to responsibly manage pensions ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level .
does this mean defined benefit pension plans will become dramatically underfunded all over again - at all levels of government including federal ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
and so you have these liabilities , and you see that they 're getting less and less well funded . so if we go right over here , this is what this green line is , the funding ratio . so how well funded are these liabilities ?
what is ma 's under funding percentage ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
it 's getting pretty much no interest . if you 're in a low interest rate environment , if you 're not getting good returns -- and a lot of pensions tend to go into very safe assets , but those are getting very low returns . you 're going to have to set aside more money , and so you see these obligations essentially ju...
we are always in a low rate but why ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
so for example -- actually , texas , for example , 83 % of their pension liabilities are funded . they 've set aside 83 % of the right amount of money to fund their pension obligations , not 100 % . it is underfunded , but it 's not crazy .
why does your discussion assume that the only way a state can meet its pension obligations is by giving money to the private sector to invest ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
and there 's a lot of things that go into the total liabilities , the same things that we talked about in the last video . there are things like return on investment . if you are in a low interest rate environment , like we are now -- for example , my money in my savings account , i think , is getting like 0.4 % intere...
what would be wrong with paying-as-you-go : that is , paying each year 's obligations to retirees in the years in which they are entitled to pensions , instead of entering the weird world of predictions of ( a ) future benefit starting amounts , ( b ) future inflations rates , ( c ) future rates of investment return ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
what is the recommended level of funding by defined benefit plans ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
these are attempts at kind of factoring in inflation , how much things are costing in that region . but they are also sometimes negotiated . and sometimes , and especially in the case of illinois , they 've grown faster than the rate of inflation .
also does n't the funding level get tricky with the return on investments being harder to project ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
so for example -- actually , texas , for example , 83 % of their pension liabilities are funded . they 've set aside 83 % of the right amount of money to fund their pension obligations , not 100 % . it is underfunded , but it 's not crazy .
was the illinois pension fund invested in less safe investments than most pension funds and thus lost a lot of money during the 2008 financial crisis ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
and so you have these liabilities , and you see that they 're getting less and less well funded . so if we go right over here , this is what this green line is , the funding ratio . so how well funded are these liabilities ?
what is massachusetts u.f ( under funding ) percentage ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
if you are in a low interest rate environment , like we are now -- for example , my money in my savings account , i think , is getting like 0.4 % interest . it 's getting pretty much no interest . if you 're in a low interest rate environment , if you 're not getting good returns -- and a lot of pensions tend to go int...
how much of the 2010 pension shortfall is artificially low because it is reflecting the low market value of stocks , funds , and other investments in 2010 because of the financial crisis in 2008 ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
it 's the ratio of this part right over here to the entire bar . and you see right over here , illinois is in a bad situation . their total liabilities are 138 billion .
is the situation in ct similar to that described for illinois ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so right over here is a map of , obviously , the united states . and what it shows is how funded the pension liabilities are in the different states .
why is puerto rico not included in the map ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
and you see right over here , illinois is in a bad situation . their total liabilities are 138 billion . this is in millions , so it 's 138,000 million .
what are the benifits to not paying your prompised liabilities ?
in the last video , we talked about pensions and how they 're defined benefit plans and how they could to get underfunded or how there could be temptation for people to underfund them . in this video , i want to make things a little bit more concrete by looking at actual numbers , especially at the state level . so rig...
this is the state universities retirement system . this is the state employees retirement system . this is the judges retirement system . you see there 's a lot fewer judges than that .
why do governments utilize a different accounting system than private businesses ?
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ? all right , this is interesting . so , one way i could think about doing this is , well let 's just try each of these f of xes . if this is , if this was f ...
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ?
what is a domain and range ?
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ? all right , this is interesting . so , one way i could think about doing this is , well let 's just try each of these f of xes . if this is , if this was f ...
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ?
hi , my question is , how is x equal to g ( x ) ?
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ? all right , this is interesting . so , one way i could think about doing this is , well let 's just try each of these f of xes . if this is , if this was f ...
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ?
i understand how you solve a function using operations , but how do you interpret the graph of a function ?
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ? all right , this is interesting . so , one way i could think about doing this is , well let 's just try each of these f of xes . if this is , if this was f ...
let g of x , let g of x equal x squared minus five . if f of g of x is equal to the square root of x squared plus four , which of the following describes f of x ?
how do you know what the value of a function is by looking at its graph ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
was the intuition of the mathematicians who defined matrix addition really that arbitrary ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
can matrices be considered as vectors , in a way , with the addition and subtraction properties of matrices being similar to that of vectors ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
now let me ask you an interesting question . what if i wanted to subtract matrices ? so let 's once again think about matrices that have the same dimensions .
what are matrices used for ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
what is the point of a matrix ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
`` okay sal , i understand when i 'm adding or subtracting matrices with the same dimensions i just add or subtract the corresponding terms . but what happens when i have matrices with different dimensions ? '' so , for example , what about the scenario where i want to add the matrix one , zero , three , five , zero , ...
could there ever be a situation when you have to add or subtract matrices of different dimensions ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition .
what are the point of matrixes ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
so let 's once again think about matrices that have the same dimensions . so let 's say i 'm gon na do then two two-by-two matrices . so let 's say it 's zero , one , three , two , and from that i want to subtract negative one , three , zero , and five .
i understand why you would n't be able to put the matrices in any order while dividing , but since multiplying is simply repeated addition , would n't the order of two matrices not matter ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
and you 'll see that you get the exact same thing here . when you multiply negative one times negative one you get positive one , positive one plus zero is one . negative one times three plus one is negative two .
can we divide a matrice with one other ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
so if you were one of these mathematicians who were first defining how matrices should be added , how would you define adding this first matrix over here to the second one ? well , the most common-sense thing that might have jumped out at you – especially because these two matrices have the same dimensions – ( this is ...
if i want to add two matrices with dimensions 3 x 2 and 2 x 3 , can i transpose one of them to get two matrices with dimensions 3 x 2 and 3 x 2 and then perform addition ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
`` okay sal , i understand when i 'm adding or subtracting matrices with the same dimensions i just add or subtract the corresponding terms . but what happens when i have matrices with different dimensions ? '' so , for example , what about the scenario where i want to add the matrix one , zero , three , five , zero , ...
or is it that such kinds of matrices with different dimensions can never be added ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
there might be a question that is lingering in your brain right now . `` okay sal , i understand when i 'm adding or subtracting matrices with the same dimensions i just add or subtract the corresponding terms . but what happens when i have matrices with different dimensions ? '' so , for example , what about the scena...
so if adding and subtracting different dimensional matrices is undefined , can you multiply and divide ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
you can add five plus three to get eight . you can add -and i 'm running out of colours here- you could add zero plus eleven to get eleven . you can add three to negative one to get two .
why ca n't you just put a zero in all the missing places and then add all the others ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
now let me ask you an interesting question . what if i wanted to subtract matrices ? so let 's once again think about matrices that have the same dimensions .
can we use properties such as the associative property or the distributive property while working with matrices ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
now let me ask you an interesting question . what if i wanted to subtract matrices ? so let 's once again think about matrices that have the same dimensions .
how do find the additive inverse of matrices ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
`` okay sal , i understand when i 'm adding or subtracting matrices with the same dimensions i just add or subtract the corresponding terms . but what happens when i have matrices with different dimensions ? '' so , for example , what about the scenario where i want to add the matrix one , zero , three , five , zero , ...
to add or subtract matrices of different dimensions , why would n't it work to fill in zeros in the matrices ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
that the addition of matrices should literally just be adding the corresponding entries . so in this situation , we would add 1 + 5 to get the corresponding entry in the sum – which is 6 . you can add negative seven plus zero to get negative seven .
why is there a `` d '' after the equals sign ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
well it turns out that the mathematical mainstream does not define this . this is undefined . this is undefined .
is it just khan making a smiley face or is it used to indicate the sat choice `` d. undefined '' ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
well , the most common-sense thing that might have jumped out at you – especially because these two matrices have the same dimensions – ( this is a 2-by-3 matrix . it has 2 rows and 3 columns . this is also a 2-by-3 matrix .
why ca n't we add zero as a place-holder for any missing rows/columns ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
how do you know if a matrix is unsolvable ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
i could 've done this the other way around , if i did this the other way around -so let me copy and paste this- so if i were to add this matrix -so let me copy , let me paste it- if i were to add that matrix to -let me copy and paste the other one- this matrix , copy and paste , you 'll see that the order in which i 'm...
does the size of a and b have to be the same in order to do these operations ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
that the addition of matrices should literally just be adding the corresponding entries . so in this situation , we would add 1 + 5 to get the corresponding entry in the sum – which is 6 . you can add negative seven plus zero to get negative seven .
for instance , could n't we rewrite the 2x2 matrix [ 5 7 ; -1 6 ] as a 3x2 [ 5 7 ; -1 6 ; 0 0 ] ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
well it turns out that the mathematical mainstream does not define this . this is undefined . this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logical...
if the addition and subtraction of different dimension matrices is undefined , is the same true for multiplication ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
now let me ask you an interesting question . what if i wanted to subtract matrices ? so let 's once again think about matrices that have the same dimensions .
is it possible to multiply and divide matrices ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
`` okay sal , i understand when i 'm adding or subtracting matrices with the same dimensions i just add or subtract the corresponding terms . but what happens when i have matrices with different dimensions ? '' so , for example , what about the scenario where i want to add the matrix one , zero , three , five , zero , ...
when dealing with arrays of different lengths ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
is it possible to divide or square root a matrix ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
well , the most common-sense thing that might have jumped out at you – especially because these two matrices have the same dimensions – ( this is a 2-by-3 matrix . it has 2 rows and 3 columns . this is also a 2-by-3 matrix .
can there be a third variable of some sort in a matrix besides rows and columns ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
now let me ask you an interesting question . what if i wanted to subtract matrices ? so let 's once again think about matrices that have the same dimensions .
how do you enter matrices into the computer ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
so let 's once again think about matrices that have the same dimensions . so let 's say i 'm gon na do then two two-by-two matrices . so let 's say it 's zero , one , three , two , and from that i want to subtract negative one , three , zero , and five .
do two matrixes have to have the same dimensions to be added ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
it has 2 rows and 3 columns . this is also a 2-by-3 matrix . it also has 2 rows and 3 columns . )
waht would be the sum of 3+ [ a matrix ] ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
how do you do scalar matrix addition and subtraction ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
`` okay sal , i understand when i 'm adding or subtracting matrices with the same dimensions i just add or subtract the corresponding terms . but what happens when i have matrices with different dimensions ? '' so , for example , what about the scenario where i want to add the matrix one , zero , three , five , zero , ...
why is it then not possible to add two matrices with different dimensions in this aggregate way ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
now let me ask you an interesting question . what if i wanted to subtract matrices ? so let 's once again think about matrices that have the same dimensions .
how do you use matrices to solve nonmatrix problems in real life ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
for matrices with different dimensions , for instance a 2x3 matrix and 2x2 matrix , why ca n't we consider the latter to have a third column with all entries equal to zero so that we can add the two matrices ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
that the addition of matrices should literally just be adding the corresponding entries . so in this situation , we would add 1 + 5 to get the corresponding entry in the sum – which is 6 . you can add negative seven plus zero to get negative seven .
would you change pi to 3.14 and add ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
but what happens when i have matrices with different dimensions ? '' so , for example , what about the scenario where i want to add the matrix one , zero , three , five , zero , one to the matrix -so this a three-by-two matrix- and i wan na add it to , let 's say , a two-by-two matrix . five , seven , negative one , ze...
what if i wanted to add a 3x4 matrix to a 12x1 matrix ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
that the addition of matrices should literally just be adding the corresponding entries . so in this situation , we would add 1 + 5 to get the corresponding entry in the sum – which is 6 . you can add negative seven plus zero to get negative seven .
would [ 6 7 8 ] - [ 5 ] be undefined ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
when you multiply negative one times negative one you get positive one , positive one plus zero is one . negative one times three plus one is negative two . fair enough .
while multiplying two numbers with both negative signs , will it turn positive in the product part or negative ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
and if that was your intuition , then you had the same intuition as the mathematical mainstream . that the addition of matrices should literally just be adding the corresponding entries . so in this situation , we would add 1 + 5 to get the corresponding entry in the sum – which is 6 .
is the final result of adding/subracting matrices always going to have only 1 column ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
what does the word `` arbitrary '' mean ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
`` okay sal , i understand when i 'm adding or subtracting matrices with the same dimensions i just add or subtract the corresponding terms . but what happens when i have matrices with different dimensions ? '' so , for example , what about the scenario where i want to add the matrix one , zero , three , five , zero , ...
so you ca n't add matrices of different dimensions ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
is it possible for a matrix to have a complex number in it ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
and you 'll see that you get the exact same thing here . when you multiply negative one times negative one you get positive one , positive one plus zero is one . negative one times three plus one is negative two .
at the last part of the video , could n't you just expand one of the matrices by writing in 0 's ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
could n't the dimensions be added or subtracted the same way as the numbers within the matrix ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
are there any operations that can reduce or increase the initial size of an matrix ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
is matrix addition is possible when there is the number of rows or columns are different ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
how do you multiply a number by a matrix ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
what is an arbitrary number ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
this is undefined . so we do not define matrix addition , or matrix subtraction , when the matrices have different dimensions . there did n't seem to be any reasonable way to do this , that would actually be useful and logically consistent in some nice way .
i still ca n't figure out matrices where a matrix + b matrix = c matrix and it 's asking me to solve for x and y ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
now let me ask you an interesting question . what if i wanted to subtract matrices ? so let 's once again think about matrices that have the same dimensions .
how do you solve matrices with variables ?
let 's think about how we can define `` matrix addition . '' and mathematicians could have chosen any of an arbitrary number of ways to define addition . but they 've picked a way to define addition that seems – one – to make sense , and it also has nice properties that allow us to do interesting things with matrices l...
and that indeed is how you can define matrix subtraction . in fact you do n't even have to define matrix subtraction , you can let this fall out of what we did with scalar multiplication and matrix addition . we can view as the exact same thing -this as the exact same thing- as taking zero , one , three , two and to th...
the identity matrix can serve as a scalar , so why ca n't composed matrices be converted to bigger sizes ?