# How do you solve 8-8a^2=-792?

Aug 15, 2016

$a = \pm 10$

#### Explanation:

$8 - 8 {a}^{2} = - 792$

$8 {a}^{2} = 800$

${a}^{2} = 100$

$a = \pm \sqrt{100}$

$a = \pm 10$

Aug 15, 2016

a=±10

#### Explanation:

What we want to do here is isolate the $- 8 {a}^{2}$ term on the left side of the equation while having the numeric value on the right.

To do this subtract 8 from both sides.

$\cancel{8} \cancel{- 8} - 8 {a}^{2} = - 792 - 8$

$\Rightarrow - 8 {a}^{2} = - 800$

now divide both sides by -8

$\frac{{\cancel{- 8}}^{1} {a}^{2}}{\cancel{- 8}} = \frac{{\cancel{- 800}}^{100}}{\cancel{- 8}} ^ 1 \Rightarrow {a}^{2} = 100$

now take the 'square root' of both sides

sqrt(a^2)=±sqrt100rArra=±10