5m(4m+9)=0

Solution for 5m(4m+9)=0 equation:

5m(4m+9)=0

We multiply parentheses

20m^2+45m=0

a = 20; b = 45; c = 0;
Δ = b2-4ac
Δ = 452-4·20·0
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*20}=\frac{-90}{40}
=-2+1/4
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(45)+45}{2*20}=\frac{0}{40}
=0
$