-4a^2+32a-60=0

Solution for -4a^2+32a-60=0 equation:

-4a^2+32a-60=0

a = -4; b = 32; c = -60;
Δ = b2-4ac
Δ = 322-4·(-4)·(-60)
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(32)-8}{2*-4}=\frac{-40}{-8}
=+5
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(32)+8}{2*-4}=\frac{-24}{-8}
=+3
$