15x^2-60x-2040=0

Solution for 15x^2-60x-2040=0 equation:

15x^2-60x-2040=0

a = 15; b = -60; c = -2040;
Δ = b2-4ac
Δ = -602-4·15·(-2040)
Δ = 126000
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:

$\sqrt{\Delta}=\sqrt{126000}=\sqrt{3600*35}=\sqrt{3600}*\sqrt{35}=60\sqrt{35}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-60\sqrt{35}}{2*15}=\frac{60-60\sqrt{35}}{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+60\sqrt{35}}{2*15}=\frac{60+60\sqrt{35}}{30}
$