#### Answer

$11x\sqrt[3]{4x}$

#### Work Step by Step

$x\sqrt[3]{32x}+9\sqrt[3]{4x^4}$
Factor out perfect cubes.
$x\sqrt[3]{(8)(4)(x)}+9\sqrt[3]{4x^3x}$
Simplify.
$x(2)\sqrt[3]{4x}+9(x)\sqrt[3]{4x}$
$2x\sqrt[3]{4x}+9x\sqrt[3]{4x}$
Add like radicals.
$11x\sqrt[3]{4x}$