Answer
$(x+y)\sqrt[3]{x+y}$
Work Step by Step
RECALL:
$\sqrt[3]{a^3}=a$
Factor the radicand (expression inside the radical sign) so that at least one factor is a perfect cube, and then use the rule above to simplify and obtain:
$=\sqrt[3]{(x+y)^3\cdot (x+y)}
\\=(x+y)\sqrt[3]{x+y}$
