(y+4)(9y+8)=0

Solution for (y+4)(9y+8)=0 equation:

(y+4)(9y+8)=0

We multiply parentheses ..

(+9y^2+8y+36y+32)=0

We get rid of parentheses

9y^2+8y+36y+32=0

We add all the numbers together, and all the variables

9y^2+44y+32=0

a = 9; b = 44; c = +32;
Δ = b2-4ac
Δ = 442-4·9·32
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(44)-28}{2*9}=\frac{-72}{18}
=-4
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(44)+28}{2*9}=\frac{-16}{18}
=-8/9
$