y(-8-2y)=4

Solution for y(-8-2y)=4 equation:

y(-8-2y)=4

We move all terms to the left:

y(-8-2y)-(4)=0

We add all the numbers together, and all the variables

y(-2y-8)-4=0

We multiply parentheses

-2y^2-8y-4=0

a = -2; b = -8; c = -4;
Δ = b2-4ac
Δ = -82-4·(-2)·(-4)
Δ = 32
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:

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