20x^2+50x-120=0

Solution for 20x^2+50x-120=0 equation:

20x^2+50x-120=0

a = 20; b = 50; c = -120;
Δ = b2-4ac
Δ = 502-4·20·(-120)
Δ = 12100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12100}=110$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(50)-110}{2*20}=\frac{-160}{40}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(50)+110}{2*20}=\frac{60}{40}
=1+1/2
$