-8z^2+8z+6=0

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

-8z^2+8z+6=0

a = -8; b = 8; c = +6;
Δ = b2-4ac
Δ = 82-4·(-8)·6
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-16}{2*-8}=\frac{-24}{-16}
=1+1/2
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+16}{2*-8}=\frac{8}{-16}
=-1/2
$