3x^2+120x-1600=0

Solution for 3x^2+120x-1600=0 equation:

3x^2+120x-1600=0

a = 3; b = 120; c = -1600;
Δ = b2-4ac
Δ = 1202-4·3·(-1600)
Δ = 33600
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:

$\sqrt{\Delta}=\sqrt{33600}=\sqrt{1600*21}=\sqrt{1600}*\sqrt{21}=40\sqrt{21}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(120)-40\sqrt{21}}{2*3}=\frac{-120-40\sqrt{21}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(120)+40\sqrt{21}}{2*3}=\frac{-120+40\sqrt{21}}{6}
$