# How do you factor  y = x^3 -10x -12?

Oct 9, 2015

Factor $y = {x}^{3} - 10 x - 12$

Ans: $y = \left(x + 2\right) \left({x}^{2} - 2 x - 6\right)$

#### Explanation:

Substitute x = -2 into the function, we get f(-2) = 0. Then (x + 2) is a factor.
By division, we get:
$y = \left(x + 2\right) \left({x}^{2} - 2 x - 6\right)$
The trinomial can't be factored because its D = 4 + 24 = 28 is not a perfect square.
Therefor: $y = \left(x + 2\right) \left({x}^{2} - 2 x - 6\right)$