15x^2-30x-1800=0

Solution for 15x^2-30x-1800=0 equation:

15x^2-30x-1800=0

a = 15; b = -30; c = -1800;
Δ = b2-4ac
Δ = -302-4·15·(-1800)
Δ = 108900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{108900}=330$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-330}{2*15}=\frac{-300}{30}
=-10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+330}{2*15}=\frac{360}{30}
=12
$