0=-2x^2+16x+18-2x^2+16x+18

Solution for 0=-2x^2+16x+18-2x^2+16x+18 equation:

0=-2x^2+16x+18-2x^2+16x+18

We move all terms to the left:

0-(-2x^2+16x+18-2x^2+16x+18)=0

We add all the numbers together, and all the variables

-(-2x^2+16x+18-2x^2+16x+18)=0

We get rid of parentheses

2x^2+2x^2-16x-16x-18-18=0

We add all the numbers together, and all the variables

4x^2-32x-36=0

a = 4; b = -32; c = -36;
Δ = b2-4ac
Δ = -322-4·4·(-36)
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-32)-40}{2*4}=\frac{-8}{8}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-32)+40}{2*4}=\frac{72}{8}
=9
$