Answer
$x^{2}(x+3)$
Work Step by Step
We are given the polynomial $x^{3}+3x^{2}$. The GCF of both terms is$x^{2}$, so we can factor $x^{2}$ out from each term.
$x^{2}(x)+x^{2}(3)$
Next, we can apply the distributive property.
$x^{2}(x+3)$