x*x-9=-8x+8

Solution for x*x-9=-8x+8 equation:

x*x-9=-8x+8

We move all terms to the left:

x*x-9-(-8x+8)=0

Wy multiply elements

x^2-(-8x+8)-9=0

We get rid of parentheses

x^2+8x-8-9=0

We add all the numbers together, and all the variables

x^2+8x-17=0

a = 1; b = 8; c = -17;
Δ = b2-4ac
Δ = 82-4·1·(-17)
Δ = 132
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{132}=\sqrt{4*33}=\sqrt{4}*\sqrt{33}=2\sqrt{33}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-2\sqrt{33}}{2*1}=\frac{-8-2\sqrt{33}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+2\sqrt{33}}{2*1}=\frac{-8+2\sqrt{33}}{2}
$