# How do you solve x^2 = 7x +8 using the quadratic formula?

Apr 11, 2016

-1 and 8

#### Explanation:

$y = {x}^{2} - 7 x - 8 = 0$
Since (a - b + c = 0), use shortcut.
The 2 real roots are: - 1 and $- \frac{c}{a} = 8.$

Reminder of Shortcut.

• When a + b + c = 0 --> 2 real roots: 1 and $\frac{c}{a}$
• When a - b + c = 0 --> 2 real roots: -1 and $- \frac{c}{a}$