Answer
$\dfrac{5\sqrt{m}+5\sqrt{5}}{m-5}$
Work Step by Step
Rationalize the denominator by multiplying $\sqrt{m}+\sqrt{5}$ to both the numerator and the denominator to have:
$=\dfrac{5}{\sqrt{m}-\sqrt{5}} \cdot \dfrac{\sqrt{m}+\sqrt{5}}{\sqrt{m}+\sqrt{5}}
\\=\dfrac{5\sqrt{m}+5\sqrt{5}}{m-5}$
