576=20x+x^2

Solution for 576=20x+x^2 equation:

576=20x+x^2

We move all terms to the left:

576-(20x+x^2)=0

We get rid of parentheses

-x^2-20x+576=0

We add all the numbers together, and all the variables

-1x^2-20x+576=0

a = -1; b = -20; c = +576;
Δ = b2-4ac
Δ = -202-4·(-1)·576
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-52}{2*-1}=\frac{-32}{-2}
=+16
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+52}{2*-1}=\frac{72}{-2}
=-36
$