00:04
Now to find the determinant of this 3x3 matrix, first let's circle the first number of the first row.
00:14
And this multiplies the denominator of, okay, we're eliminating the same row and same column, and we left a 2x2 small matrix.
00:24
So 1 times the determinant of this 2x2 matrix.
00:32
And then, okay, let's circle the second number.
00:38
Of the first row.
00:41
Okay, so the second number of the first row is negative 5.
00:47
So we eliminated the same row and eliminated the same column, and i have minus negative.
00:54
Okay, here's when you change the sign, okay, negative.
00:57
So minus negative times this 2x2 small metrics, which is 3034...