-90x^2+1380x=0

Solution for -90x^2+1380x=0 equation:

-90x^2+1380x=0

a = -90; b = 1380; c = 0;
Δ = b2-4ac
Δ = 13802-4·(-90)·0
Δ = 1904400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1904400}=1380$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1380)-1380}{2*-90}=\frac{-2760}{-180}
=15+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1380)+1380}{2*-90}=\frac{0}{-180}
=0
$