-9(x+1)(x+5)=0

Solution for -9(x+1)(x+5)=0 equation:

-9(x+1)(x+5)=0

We multiply parentheses ..

-9(+x^2+5x+x+5)=0

We multiply parentheses

-9x^2-45x-9x-45=0

We add all the numbers together, and all the variables

-9x^2-54x-45=0

a = -9; b = -54; c = -45;
Δ = b2-4ac
Δ = -542-4·(-9)·(-45)
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-54)-36}{2*-9}=\frac{18}{-18}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-54)+36}{2*-9}=\frac{90}{-18}
=-5
$