72=6s^2-2s

Solution for 72=6s^2-2s equation:

72=6s^2-2s

We move all terms to the left:

72-(6s^2-2s)=0

We get rid of parentheses

-6s^2+2s+72=0

a = -6; b = 2; c = +72;
Δ = b2-4ac
Δ = 22-4·(-6)·72
Δ = 1732
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1732}=\sqrt{4*433}=\sqrt{4}*\sqrt{433}=2\sqrt{433}$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{433}}{2*-6}=\frac{-2-2\sqrt{433}}{-12}
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{433}}{2*-6}=\frac{-2+2\sqrt{433}}{-12}
$