15x^2+20x=180

Solution for 15x^2+20x=180 equation:

15x^2+20x=180

We move all terms to the left:

15x^2+20x-(180)=0

a = 15; b = 20; c = -180;
Δ = b2-4ac
Δ = 202-4·15·(-180)
Δ = 11200
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:

$\sqrt{\Delta}=\sqrt{11200}=\sqrt{1600*7}=\sqrt{1600}*\sqrt{7}=40\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-40\sqrt{7}}{2*15}=\frac{-20-40\sqrt{7}}{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+40\sqrt{7}}{2*15}=\frac{-20+40\sqrt{7}}{30}
$