-16x^2+60x+40=0

Solution for -16x^2+60x+40=0 equation:

-16x^2+60x+40=0

a = -16; b = 60; c = +40;
Δ = b2-4ac
Δ = 602-4·(-16)·40
Δ = 6160
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:

$\sqrt{\Delta}=\sqrt{6160}=\sqrt{16*385}=\sqrt{16}*\sqrt{385}=4\sqrt{385}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(60)-4\sqrt{385}}{2*-16}=\frac{-60-4\sqrt{385}}{-32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(60)+4\sqrt{385}}{2*-16}=\frac{-60+4\sqrt{385}}{-32}
$