2y^2+18y-70=-4

Solution for 2y^2+18y-70=-4 equation:

2y^2+18y-70=-4

We move all terms to the left:

2y^2+18y-70-(-4)=0

We add all the numbers together, and all the variables

2y^2+18y-66=0

a = 2; b = 18; c = -66;
Δ = b2-4ac
Δ = 182-4·2·(-66)
Δ = 852
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:

$\sqrt{\Delta}=\sqrt{852}=\sqrt{4*213}=\sqrt{4}*\sqrt{213}=2\sqrt{213}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-2\sqrt{213}}{2*2}=\frac{-18-2\sqrt{213}}{4}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+2\sqrt{213}}{2*2}=\frac{-18+2\sqrt{213}}{4}
$