5m(m+7.2)=180

Solution for 5m(m+7.2)=180 equation:

5m(m+7.2)=180

We move all terms to the left:

5m(m+7.2)-(180)=0

We multiply parentheses

5m^2+36m-180=0

a = 5; b = 36; c = -180;
Δ = b2-4ac
Δ = 362-4·5·(-180)
Δ = 4896
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4896}=\sqrt{144*34}=\sqrt{144}*\sqrt{34}=12\sqrt{34}$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(36)-12\sqrt{34}}{2*5}=\frac{-36-12\sqrt{34}}{10}
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+12\sqrt{34}}{2*5}=\frac{-36+12\sqrt{34}}{10}
$