x^2-22x-720=0

Solution for x^2-22x-720=0 equation:

x^2-22x-720=0

a = 1; b = -22; c = -720;
Δ = b2-4ac
Δ = -222-4·1·(-720)
Δ = 3364
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3364}=58$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-22)-58}{2*1}=\frac{-36}{2}
=-18
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-22)+58}{2*1}=\frac{80}{2}
=40
$