-4x^2-36x+100=0

Solution for -4x^2-36x+100=0 equation:

-4x^2-36x+100=0

a = -4; b = -36; c = +100;
Δ = b2-4ac
Δ = -362-4·(-4)·100
Δ = 2896
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:

$\sqrt{\Delta}=\sqrt{2896}=\sqrt{16*181}=\sqrt{16}*\sqrt{181}=4\sqrt{181}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-4\sqrt{181}}{2*-4}=\frac{36-4\sqrt{181}}{-8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+4\sqrt{181}}{2*-4}=\frac{36+4\sqrt{181}}{-8}
$