00:02
Okay, this question wants us to verify this following identity, using the fact that if we swap rows in a matrix, then the determinant sign also flips.
00:18
So, in our first example, we can see this, because the right side decided to flip rows 2 and 3.
00:34
So, since we swapped row 2 and row 3, our determinant swap sign also.
00:59
Then we can verify that both of these determinants are equal to 100.
01:09
Well, the left side is negative 115, and the right side is positive 115, by punching this into our calculator and calculating its determinant that way.
01:23
So again, this is a.
01:26
We can see that 115 equals negative times 115...