Chapter R - Section R.8 - nth Roots; Rational Exponents - R.8 Assess Your Understanding - Page 78: 47

$(-x-5y)\sqrt[3]{2xy}=-(x+5y)\sqrt[3]{2xy}$

We simplify: $\sqrt[3]{16x^4y}-3x\sqrt[3]{2xy}+5\sqrt[3]{-2xy^4}=\sqrt[3]{8*2x^3xy}-3x\sqrt[3]{2xy}+5\sqrt[3]{-1*2xy^3y}=2x\sqrt[3]{2xy}-3x\sqrt[3]{2xy}-5y\sqrt[3]{2xy}=(2x-3x-5y)\sqrt[3]{2xy}=(-x-5y)\sqrt[3]{2xy}=-(x+5y)\sqrt[3]{2xy}$