x2-28x-480=0

Solution for x2-28x-480=0 equation:

x2-28x-480=0

We add all the numbers together, and all the variables

x^2-28x-480=0

a = 1; b = -28; c = -480;
Δ = b2-4ac
Δ = -282-4·1·(-480)
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{-(-28)-52}{2*1}=\frac{-24}{2}
=-12
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+52}{2*1}=\frac{80}{2}
=40
$