480-8x=60+5x+x^2

Solution for 480-8x=60+5x+x^2 equation:

480-8x=60+5x+x^2

We move all terms to the left:

480-8x-(60+5x+x^2)=0

We get rid of parentheses

-x^2-5x-8x-60+480=0

We add all the numbers together, and all the variables

-1x^2-13x+420=0

a = -1; b = -13; c = +420;
Δ = b2-4ac
Δ = -132-4·(-1)·420
Δ = 1849
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1849}=43$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-13)-43}{2*-1}=\frac{-30}{-2}
=+15
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-13)+43}{2*-1}=\frac{56}{-2}
=-28
$