## Precalculus (6th Edition) Blitzer

$2x$
Using the properties of radicals and exponents, the given expression simplifies to $\sqrt[5]{\dfrac{64x^6}{2x}} \\=\sqrt[5]{32x^{6-1}} \\=\sqrt[5]{32x^5} \\=\sqrt[5]{2^5x^5} \\=\sqrt[5]{(2x)^5} \\=2x.$