-10x^2-56x+36=0

Solution for -10x^2-56x+36=0 equation:

-10x^2-56x+36=0

a = -10; b = -56; c = +36;
Δ = b2-4ac
Δ = -562-4·(-10)·36
Δ = 4576
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:

$\sqrt{\Delta}=\sqrt{4576}=\sqrt{16*286}=\sqrt{16}*\sqrt{286}=4\sqrt{286}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-4\sqrt{286}}{2*-10}=\frac{56-4\sqrt{286}}{-20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+4\sqrt{286}}{2*-10}=\frac{56+4\sqrt{286}}{-20}
$