#### Answer

$\sqrt{\dfrac{2x}{5y}}=\dfrac{\sqrt{10xy}}{5y}$

#### Work Step by Step

$\sqrt{\dfrac{2x}{5y}}$
Rewrite the expression as $\dfrac{\sqrt{2x}}{\sqrt{5y}}$:
$\sqrt{\dfrac{2x}{5y}}=\dfrac{\sqrt{2x}}{\sqrt{5y}}=...$
Multiply the fraction by $\dfrac{\sqrt{5y}}{\sqrt{5y}}$ and simplify:
$...=\dfrac{\sqrt{2x}}{\sqrt{5y}}\cdot\dfrac{\sqrt{5y}}{\sqrt{5y}}=\dfrac{\sqrt{10xy}}{\sqrt{(5y)^{2}}}=\dfrac{\sqrt{10xy}}{5y}$