#### Answer

$2y\sqrt[3] {2x}$

#### Work Step by Step

$\sqrt[3] {54xy^3}-5\sqrt[3] {2xy^3}+y\sqrt[3] {128x}$ Factor.
$\sqrt[3] {27y^3}\sqrt[3] {2x}-5\sqrt[3] {y^3}\sqrt[3] {2x}+y\sqrt[3] {64}\sqrt[3] {2x}$ Simplify.
$3y\sqrt[3] {2x}-5y\sqrt[3] {2x}+4y\sqrt[3] {2x}$ Combine like radicals.
$2y\sqrt[3] {2x}$