00:01
So suppose i have two matrices, and i want to solve this matrix equation for x.
00:07
So it may look a little confusing, but all i'm going to do is just treat a and b like variables or like other constants.
00:16
And i'm just going to solve this equation, give matrix x by itself.
00:20
So what would you do first? if this was just an equation, trying to get x by itself, i'd move over this 5a, opposite of adding this attracting.
00:27
Whatever due to one side, i got it to the other.
00:29
This gives me two matrix x can i combine b and an a no they're different variables matrix b minus 5 times matrix a then what i do from here is x completely by itself no it's multiplied by two okay i need to get rid of that two opposite of multiplying dividing and i'm going to do this to each of these terms so really matrix x is just found one half times matrix b minus 5 over 2 or plus negative 5 over 2 times matrix a.
01:02
So i just have to do a bunch of matrix operations to find this.
01:05
So first, let's find one -half times b.
01:09
So one -half times matrix b to multiply a matrix.
01:13
All i'm going to do is multiply each of these terms by one -half and solve from there.
01:21
Okay.
01:21
So this will be negative 5 over 2, anything times 0, 3 over 2, negative 1 -half, 0.
01:31
And negative 4 over 2, 0, and negative 4 4 over 2 or negative 2, i'm going to leave it as a fraction for now, plus now i want to find negative 5 over 2 times a.
01:41
So i'm going to multiply each of these by negative 5 over 2.
01:47
Okay, doing this.
01:53
So negative 5 over 2, negative times negative is positive, positive 15 over 2.
01:58
This will be negative or positive 10 over 2.
02:06
This will be negative 25 over 2, right? 5 times 7, positive 35...