00:01
Alright, let's set the following up as a matrix.
00:02
So we have 1, 2, 1, 1, 2, 1, 2, 2, 2, 3, 1, 3, 1, 3.
00:14
All right, we're going to use our first row to cancel out the numbers below it.
00:21
So row 2 minus double row 1, and row 3 minus triple row 1.
00:31
So first row is not changing.
00:34
Second row, 2 minus 2 is 0, negative 1 minus 4 is negative 5, 2 minus 2 is 0, and 2 minus 2 is 0.
00:51
And then in our last row, we've got 3 minus 3 is 0, 1 minus 6 is negative 5, 3 minus 3 is 0, 3 minus 3 is 0.
01:11
We'll just use our second row here to cancel out.
01:25
We'll just go through.
01:29
We can see the two rows are the same, so it's just going to cancel them out.
01:33
1 -2 -1 -1 -1 -0 -0 -0 -0.
01:38
0 -0 -0.
01:39
But we're still fine...