x^2+20=2x^2-10x-36

Solution for x^2+20=2x^2-10x-36 equation:

x^2+20=2x^2-10x-36

We move all terms to the left:

x^2+20-(2x^2-10x-36)=0

We get rid of parentheses

x^2-2x^2+10x+36+20=0

We add all the numbers together, and all the variables

-1x^2+10x+56=0

a = -1; b = 10; c = +56;
Δ = b2-4ac
Δ = 102-4·(-1)·56
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-18}{2*-1}=\frac{-28}{-2}
=+14
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+18}{2*-1}=\frac{8}{-2}
=-4
$