# How do you solve for a in sqrt(a + 9)= b + 3?

Feb 14, 2016

You must square both sides to move the 9 to the other side of the equation.

#### Explanation:

$\sqrt{a + 9} = b + 3$

${\left(\sqrt{a + 9}\right)}^{2} = {\left(b + 3\right)}^{2}$

$a + 9 = {b}^{2} + 6 b + 9$

$a = {b}^{2} + 6 b \mathmr{and} a = b \left(b + 6\right)$

Hopefully this helps!