-6y^2+12y+8=0

Solution for -6y^2+12y+8=0 equation:

-6y^2+12y+8=0

a = -6; b = 12; c = +8;
Δ = b2-4ac
Δ = 122-4·(-6)·8
Δ = 336
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{336}=\sqrt{16*21}=\sqrt{16}*\sqrt{21}=4\sqrt{21}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(12)-4\sqrt{21}}{2*-6}=\frac{-12-4\sqrt{21}}{-12}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(12)+4\sqrt{21}}{2*-6}=\frac{-12+4\sqrt{21}}{-12}
$