Answer
$2x \sqrt[4]{2x}$.
Work Step by Step
$=\frac{\sqrt[4]{64x^7}}{\sqrt[4]{2x^2}}$
Use quotient rule.
$=\sqrt[4]{\frac{64x^7}{2x^2}}$
Simplify.
$=\sqrt[4]{32x^{7-2}}$
Factor as a power of $4$.
$=\sqrt[4]{2^4\cdot 2x^4x}$
Use product rule.
$=\sqrt[4]{2^4x^4}\cdot \sqrt[4]{2x}$
Simplify.
$=2x \sqrt[4]{2x}$.
