# How do you factor the expression x^3-2x^2-9x+18?

Jan 19, 2016

$f \left(x\right) = \left(x - 2\right) \left({x}^{2} - 9\right)$ = (x-2)(x-3)(x+3)
In the present case it can be easily verified that x=2 is a zero of the polynomial. Now divide the polynomial by x-2 using long or synthetic division, the quotient got would be ${x}^{2} - 9$
$f \left(x\right) = \left(x - 2\right) \left({x}^{2} - 9\right)$ = (x-2)(x-3)(x+3)