#### Answer

$\frac{13}{3} \sqrt[3]{5x}$

#### Work Step by Step

Step 1: $\sqrt[3]{\frac{5x}{27}} + 4\sqrt[3]{5x} $
Step 2: $\sqrt[3]{\frac{1}{27}}\times \sqrt[3]{5x} + 4\sqrt[3]{5x} $
Step 3: $\frac{1}{3}\times \sqrt[3]{5x} + 4\sqrt[3]{5x} $
Answer: $\frac{13}{3} \sqrt[3]{5x}$