Answer
$x(6-x)(36+6x+x^2)$
Work Step by Step
Factor out $x$ to obtain:
$=x(216-x^3)
\\=x(6^3-x^3)$
This binomial is a difference of two cubes.
RECALL:
$a^3-b^3=(a-b)(a^2+ab+b^2)$
Factor the difference of two cubes using the formula above with $a=6$ and $b=x$ to obtain:
$=x(6-x)(6^2+6(x) + x^2)
\\=x(6-x)(36+6x+x^2)$
