Answer
$-13\sqrt{6}$
Work Step by Step
The given expression is
$=2\sqrt{6}-5\sqrt{54}$
Factor as square terms.
$=2\sqrt{6}-5\sqrt{9\cdot 6}$
Use product property of square roots.
$=2\sqrt{6}-5\sqrt{9}\cdot \sqrt{6}$
Use $9=3^2$.
$=2\sqrt{6}-5\sqrt{3^2}\cdot \sqrt{6}$
Simplify.
$=2\sqrt{6}-5\cdot 3\sqrt{6}$
$=2\sqrt{6}-15\sqrt{6}$
Use distributive property.
$=(2-15)\sqrt{6}$
Subtract.
$=-13\sqrt{6}$
