256=60x+x^2

Solution for 256=60x+x^2 equation:

256=60x+x^2

We move all terms to the left:

256-(60x+x^2)=0

We get rid of parentheses

-x^2-60x+256=0

We add all the numbers together, and all the variables

-1x^2-60x+256=0

a = -1; b = -60; c = +256;
Δ = b2-4ac
Δ = -602-4·(-1)·256
Δ = 4624
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4624}=68$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-68}{2*-1}=\frac{-8}{-2}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+68}{2*-1}=\frac{128}{-2}
=-64
$