00:01
We need to factor the following.
00:02
So we're going to make u is equal to x plus three.
00:05
So we have u squared minus 9 u minus 36.
00:09
So we're going to look at the factors of negative 36.
00:13
So you have 1, negative 36, negative 13, negative 1 -36, 2, negative 18, negative 2, positive 18, 3, negative 12, negative 3 ,000, positive 12.
00:25
So that's the combination we want, because we want a combination that gives us negative 9.
00:29
So that's the 3 and the negative 12.
00:32
So we have u squared plus 3 u minus 12 u minus 36...