Answer
$\dfrac{3\sqrt[3]{4x^2}}{2x}$
Work Step by Step
Rationalizing the denominator of $
\dfrac{3}{\sqrt[3]{4x^2}}
$ results to
\begin{array}{l}
\dfrac{3}{\sqrt[3]{4x^2}}
\cdot
\dfrac{\sqrt[3]{2x}}{\sqrt[3]{2x}}
\\\\=
\dfrac{3\sqrt[3]{4x^2}}{\sqrt[3]{8x^3}}
\\\\=
\dfrac{3\sqrt[3]{4x^2}}{2x}
.\end{array}