Answer
$(x+2)(x-3)(x+3)$
Work Step by Step
$ x^{3}+2x^{2}-9x-18\qquad$...group terms with common factors.
$=(x^{3}+2x^{2})+(-9x-18)\qquad$...factor from each group.
$=x^{2}(x+2)-9(x+2)\qquad$...factor out the common binomial factor,$x+2$.
$=(x+2)(x^{2}-9)\qquad$...recognize the difference of two squares: $a^{2}-b^{2}=(a-b)(a+b)$
$=(x+2)(x-3)(x+3)$
