15x^2-80x+80=0

Solution for 15x^2-80x+80=0 equation:

15x^2-80x+80=0

a = 15; b = -80; c = +80;
Δ = b2-4ac
Δ = -802-4·15·80
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-80)-40}{2*15}=\frac{40}{30}
=1+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-80)+40}{2*15}=\frac{120}{30}
=4
$