# What is the square root of 18 plus the square root of 72?

Jul 15, 2015

=color(blue)(9sqrt2

#### Explanation:

$\sqrt{18} = \sqrt{3 \cdot 3 \cdot 2} = 3 \sqrt{2}$

$\sqrt{72} = \sqrt{2 \cdot 2 \cdot 2 \cdot 3 \cdot 3} = 6 \sqrt{2}$

$3 \sqrt{2} + 6 \sqrt{2}$
=color(blue)(9sqrt2