x^2-80x-144=0

Solution for x^2-80x-144=0 equation:

x^2-80x-144=0

a = 1; b = -80; c = -144;
Δ = b2-4ac
Δ = -802-4·1·(-144)
Δ = 6976
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{6976}=\sqrt{64*109}=\sqrt{64}*\sqrt{109}=8\sqrt{109}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-80)-8\sqrt{109}}{2*1}=\frac{80-8\sqrt{109}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-80)+8\sqrt{109}}{2*1}=\frac{80+8\sqrt{109}}{2}
$