-5m(m+9)=0

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

-5m(m+9)=0

We multiply parentheses

-5m^2-45m=0

a = -5; b = -45; c = 0;
Δ = b2-4ac
Δ = -452-4·(-5)·0
Δ = 2025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2025}=45$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-45)-45}{2*-5}=\frac{0}{-10}
=0
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-45)+45}{2*-5}=\frac{90}{-10}
=-9
$