Answer
$\sqrt 5$
Work Step by Step
The quotient rule holds that $\frac{\sqrt[n] a}{\sqrt[n] b}=\sqrt[n] (\frac{a}{b})$ (where $\sqrt[n] a$ and $\sqrt[n] b$ are real numbers and $\sqrt[n] b$ is nonzero).
Therefore, $\frac{\sqrt 45}{\sqrt 9}=\sqrt (\frac{45}{9})=\sqrt 5$