(6w-12)*w=256

Solution for (6w-12)*w=256 equation:

(6w-12)*w=256

We move all terms to the left:

(6w-12)*w-(256)=0

We multiply parentheses

6w^2-12w-256=0

a = 6; b = -12; c = -256;
Δ = b2-4ac
Δ = -122-4·6·(-256)
Δ = 6288
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{6288}=\sqrt{16*393}=\sqrt{16}*\sqrt{393}=4\sqrt{393}$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-4\sqrt{393}}{2*6}=\frac{12-4\sqrt{393}}{12}
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+4\sqrt{393}}{2*6}=\frac{12+4\sqrt{393}}{12}
$