-60x^2+1500x-4000=0

Solution for -60x^2+1500x-4000=0 equation:

-60x^2+1500x-4000=0

a = -60; b = 1500; c = -4000;
Δ = b2-4ac
Δ = 15002-4·(-60)·(-4000)
Δ = 1290000
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:

$\sqrt{\Delta}=\sqrt{1290000}=\sqrt{10000*129}=\sqrt{10000}*\sqrt{129}=100\sqrt{129}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1500)-100\sqrt{129}}{2*-60}=\frac{-1500-100\sqrt{129}}{-120}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1500)+100\sqrt{129}}{2*-60}=\frac{-1500+100\sqrt{129}}{-120}
$