-6x^2+18x+36=0

Solution for -6x^2+18x+36=0 equation:

-6x^2+18x+36=0

a = -6; b = 18; c = +36;
Δ = b2-4ac
Δ = 182-4·(-6)·36
Δ = 1188
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:

$\sqrt{\Delta}=\sqrt{1188}=\sqrt{36*33}=\sqrt{36}*\sqrt{33}=6\sqrt{33}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-6\sqrt{33}}{2*-6}=\frac{-18-6\sqrt{33}}{-12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+6\sqrt{33}}{2*-6}=\frac{-18+6\sqrt{33}}{-12}
$