Answer
$2\sqrt{5}$
Work Step by Step
Factor each radicand so that one of the factors is a perfect square to obtain:
$=\sqrt{25(5)} -\sqrt{9(5)}
\\=\sqrt{5^2(5)}-\sqrt{3^2(5)}$
Simplify each radical to obtain:
$=5\sqrt{5} - 3\sqrt{5}$
Combine like radicals to obtain:
$=(5-3)\sqrt{5}
\\=2\sqrt{5}$
