Answer
$9\sqrt{3}-6\sqrt{2}$
Work Step by Step
Simplify the radicals that can still be simplified by factoring the radicand so that one of the factors is a perfect square:
$=3\sqrt{9(3)}-2\sqrt{9(2)}
\\=3\sqrt{3^2(3)} -2\sqrt{3^2(2)}
\\=3\cdot 3\sqrt{3} -2\cdot 3\sqrt{2}
\\=9\sqrt{3}-6\sqrt{2}$