Answer
$3\sqrt{6}$
Work Step by Step
The given expression is
$=\sqrt{3}(\sqrt{72}-3\sqrt{2})$
Factor as square terms.
$=\sqrt{3}(\sqrt{36\cdot2}-3\sqrt{2})$
Use product property of square roots.
$=\sqrt{3}(\sqrt{36}\cdot \sqrt{2}-3\sqrt{2})$
Use $\sqrt {36}=6$.
$=\sqrt{3}(6\sqrt{2}-3\sqrt{2})$
Use distributive property.
$=\sqrt{3}\cdot \sqrt 2(6-3)$
Use product property of square roots.
$=\sqrt{3\cdot 2}(6-3)$
Simplify.
$=\sqrt{6}(3)$
$=3\sqrt{6}$
