(y+9)(y+13)=0

Solution for (y+9)(y+13)=0 equation:

(y+9)(y+13)=0

We multiply parentheses ..

(+y^2+13y+9y+117)=0

We get rid of parentheses

y^2+13y+9y+117=0

We add all the numbers together, and all the variables

y^2+22y+117=0

a = 1; b = 22; c = +117;
Δ = b2-4ac
Δ = 222-4·1·117
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(22)-4}{2*1}=\frac{-26}{2}
=-13
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(22)+4}{2*1}=\frac{-18}{2}
=-9
$