0=-3x^2-24x+36

Solution for 0=-3x^2-24x+36 equation:

0=-3x^2-24x+36

We move all terms to the left:

0-(-3x^2-24x+36)=0

We add all the numbers together, and all the variables

-(-3x^2-24x+36)=0

We get rid of parentheses

3x^2+24x-36=0

a = 3; b = 24; c = -36;
Δ = b2-4ac
Δ = 242-4·3·(-36)
Δ = 1008
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:

$\sqrt{\Delta}=\sqrt{1008}=\sqrt{144*7}=\sqrt{144}*\sqrt{7}=12\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(24)-12\sqrt{7}}{2*3}=\frac{-24-12\sqrt{7}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(24)+12\sqrt{7}}{2*3}=\frac{-24+12\sqrt{7}}{6}
$