-8y^2+6y+20=0

Solution for -8y^2+6y+20=0 equation:

-8y^2+6y+20=0

a = -8; b = 6; c = +20;
Δ = b2-4ac
Δ = 62-4·(-8)·20
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-26}{2*-8}=\frac{-32}{-16}
=+2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+26}{2*-8}=\frac{20}{-16}
=-1+1/4
$