Answer
$4xy^{\frac{1}{12}}$.
Work Step by Step
The given expression is
$=(64x^3y^{\frac{1}{4}})^{\frac{1}{3}}$
Raise each factor in parentheses to the $\frac{1}{3}$ power.
$=(4^3)^{\frac{1}{3}}(x^3)^{\frac{1}{3}}(y^{\frac{1}{4}})^{\frac{1}{3}}$
Use power rule.
$=4^{\frac{3}{3}}x^{\frac{3}{3}}y^{\frac{1}{4\cdot3}}$
Simplify.
$=4xy^{\frac{1}{12}}$.
