# How do you solve -5( 5+ 4a ) = 115?

Jan 25, 2018

$a = - 7$

#### Explanation:

Begin by distributing $- 5$ to each term of $\left(5 + 4 a\right)$

$\left(- 5 \cdot 5\right) + \left(- 5 \cdot 4 a\right) = 115$

$\left(- 25\right) + \left(- 20 a\right) = 115$

$- 25 - 20 a = 115$

Add $25$ to both sides:

$- 25 + 25 - 20 a = 115 + 25$

$0 - 20 a = 140$

$- 20 a = 140$

Divide both sides by $- 20$

$\frac{\cancel{- 20}}{\cancel{- 20}} a = \frac{140}{-} 20$

$a = - 7$