Answer
$\dfrac{5y}{\sqrt[3]{100xy}}$
Work Step by Step
Rationalizing the numerator of $
\dfrac{\sqrt[3]{5y^2}}{\sqrt[3]{4x}}
$ results to
\begin{array}{l}
\dfrac{\sqrt[3]{5y^2}}{\sqrt[3]{4x}}
\cdot
\dfrac{\sqrt[3]{25y}}{\sqrt[3]{25y}}
\\\\=
\dfrac{\sqrt[3]{125y^3}}{\sqrt[3]{100xy}}
\\\\=
\dfrac{5y}{\sqrt[3]{100xy}}
.\end{array}