00:01
Alright, we're going to solve the following uses inverses, so writing out our different matrixes.
00:06
Our a matrix is 1 -1 -1, 3 -2 -negative 1, 312.
00:16
Our x -matrix are our variables, so x, y, z.
00:22
Our b matrix is our solution, so 9 -8 -1.
00:29
And our inverse we found in the previous section, so we just have to make.
00:32
Match it up.
00:33
I've got them all written on the next page.
00:35
So we're looking for the one that matches to 1 -1 -1 -1.
00:38
So it's negative 5 over 7, 1 over 7, 3 over 7.
00:43
Negative 5 over 7, 1 over 7, 3 over 7.
00:53
9 over 7, 1 over 7, negative 4 over 7.
01:02
And then 3 over 7, negative 2 over 7, and 1 over 7.
01:10
Over seven, negative two over seven, one over seven.
01:14
So we're just gonna double check that again.
01:19
9 -1, negative four, three, negative two, one.
01:23
Three, negative, two, one.
01:25
Perfect.
01:26
All right, so once we have that, we're just gonna take our inverse.
01:31
Five over seven, nine over seven, three over seven, one over seven, one over seven, one over seven, negative two over seven, 3 over 7, negative 4 over 7, 1 over 7...