00:01
Here we have a system of linear equations and we're going to solve them with an augmented matrix.
00:05
So let's jump right in, make our matrix.
00:09
Column 1 is our x variable.
00:11
Volume 2 can be y, column 3 can be z, and the final column is the right -hand side.
00:25
Here's our matrix.
00:27
And now what we're going to do is first turn this 3 here.
00:34
Into a 1 and i'm going to do that by taking row 3 away from it.
00:41
So i'll have row 1 minus row 3, which is just easier for elimination later on.
00:49
So row 2 and 3 are untouched by this.
00:53
I'll fill those back in.
00:58
Row 1, this is now a 1, minus 1, 5, minus 3.
01:15
Now we can perform elimination.
01:16
On this column.
01:19
So we're going to have minus 4, row 1, added to row 2, to eliminate that 4, and minus 2, row 1 added to row 3, to eliminate about 2.
01:37
So now row 1 is going to stay the same, row 2.
01:43
Okay, so we've got 0, minus 5, minus 4, minus 1 we've got 7 minus 20 so we've got 13 and we've got 1 minus 12 we've got 13 and now for row 3 this 2 is eliminated 3 2 is 5 minus 2 minus 10 and 6 plus 6 to 12.
02:30
Like so.
02:32
Okay...