0=-2x^2+87+90

Solution for 0=-2x^2+87+90 equation:

0=-2x^2+87+90

We move all terms to the left:

0-(-2x^2+87+90)=0

We add all the numbers together, and all the variables

-(-2x^2+87+90)=0

We get rid of parentheses

2x^2-87-90=0

We add all the numbers together, and all the variables

2x^2-177=0

a = 2; b = 0; c = -177;
Δ = b2-4ac
Δ = 02-4·2·(-177)
Δ = 1416
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:

$\sqrt{\Delta}=\sqrt{1416}=\sqrt{4*354}=\sqrt{4}*\sqrt{354}=2\sqrt{354}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{354}}{2*2}=\frac{0-2\sqrt{354}}{4}
=-\frac{2\sqrt{354}}{4}
=-\frac{\sqrt{354}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{354}}{2*2}=\frac{0+2\sqrt{354}}{4}
=\frac{2\sqrt{354}}{4}
=\frac{\sqrt{354}}{2}
$