Answer
$(x+3)(x^2-3x+9)$
Work Step by Step
The given expression can be written as
$x^3+3^3.$
RECALL:
$a^3+b^3=(a+b)(a^2-ab+b^2).$
Factor the given sum of two cubes using the formula above with $a=x$ and $b=3$ to obtain
$(x+3)(x^2-x(3)+3^2)
\\=(x+3)(x^2-3x+9).$
