9y^2-36y-36=0

Solution for 9y^2-36y-36=0 equation:

9y^2-36y-36=0

a = 9; b = -36; c = -36;
Δ = b2-4ac
Δ = -362-4·9·(-36)
Δ = 2592
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:

$\sqrt{\Delta}=\sqrt{2592}=\sqrt{1296*2}=\sqrt{1296}*\sqrt{2}=36\sqrt{2}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-36\sqrt{2}}{2*9}=\frac{36-36\sqrt{2}}{18}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+36\sqrt{2}}{2*9}=\frac{36+36\sqrt{2}}{18}
$