Answer
$-\frac{1}{3c}$
Work Step by Step
=$-\frac{\sqrt{5c}}{\sqrt{45c^3}}\longrightarrow$ factor the radicand in the denominator
=$-\frac{\sqrt{5c}}{\sqrt{9c^2\times5c}}\longrightarrow$ multiplication property of square roots
=$-\frac{\sqrt{5c}}{\sqrt{9c^2}\times\sqrt{5c}}\longrightarrow$ simpify; $\sqrt{5c}$ cancels in numerator and denominator
=$-\frac{1}{3c}$
