120=6x2-6x

Solution for 120=6x2-6x equation:

120=6x^2-6x

We move all terms to the left:

120-(6x^2-6x)=0

We get rid of parentheses

-6x^2+6x+120=0

a = -6; b = 6; c = +120;
Δ = b2-4ac
Δ = 62-4·(-6)·120
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-54}{2*-6}=\frac{-60}{-12}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+54}{2*-6}=\frac{48}{-12}
=-4
$