# How do you solve  (5x + 5)^2 = 100 ?

Aug 13, 2016

$x = \frac{8}{5} , \mathmr{and} x = - \frac{12}{5}$

#### Explanation:

We do not have to multiply out the brackets first in order to solve this equation. Find the square root(s) of both sides

${\left(5 x + 5\right)}^{2} = 100$

$5 x + 2 = \pm 10$

There are two possibilities:

$5 x + 2 = + 10 \text{ or } 5 x + 2 = - 10$

$5 x = 8 \text{ } 5 x = - 12$

$x = \frac{8}{5} \text{ } x = - \frac{12}{5}$