-5x(x+9)=-5

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

-5x(x+9)=-5

We move all terms to the left:

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

We add all the numbers together, and all the variables

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

We multiply parentheses

-5x^2-45x+5=0

a = -5; b = -45; c = +5;
Δ = b2-4ac
Δ = -452-4·(-5)·5
Δ = 2125
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2125}=\sqrt{25*85}=\sqrt{25}*\sqrt{85}=5\sqrt{85}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-45)-5\sqrt{85}}{2*-5}=\frac{45-5\sqrt{85}}{-10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-45)+5\sqrt{85}}{2*-5}=\frac{45+5\sqrt{85}}{-10}
$