Answer
$\dfrac{-2}{5}$
Work Step by Step
RECALL:
For any real number $a$, $\sqrt[3]{a^3} = a$.
Write the number inside the radical sign as a cube, and then use the rule above to obtain:
$=\sqrt[3]{\left(\dfrac{-2}{5}\right)^3}
\\=\dfrac{-2}{5}$