00:01
Alright, so for this problem, in order to find the rank and nullity of the matrix, we first need to put our matrix into row -reduced echelon form.
00:11
All right, so to begin, we want to choose a convenient pivot value.
00:16
It would be our negative 1 here, but in order to make that a convenient pivot, we'll have to first multiply row 1 by negative 1.
00:26
Or pardon me, not row 1, excuse me, that's row 3.
00:28
We need to multiply row 3 by negative 1.
00:30
1.
00:32
All right, so we've flipped the signs on row 3.
00:35
The next step will be to swap row 1 and row 2.
00:42
Then, having done that, we want to use row 1 as our tool for eliminating everything else below it.
00:50
So we can see we would want to do row 2 minus 5 row 1, row 3 minus 2 row 1, and row 4 plus 8 row 1...
