3m^2-15m-72=0

Solution for 3m^2-15m-72=0 equation:

3m^2-15m-72=0

a = 3; b = -15; c = -72;
Δ = b2-4ac
Δ = -152-4·3·(-72)
Δ = 1089
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1089}=33$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-33}{2*3}=\frac{-18}{6}
=-3
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+33}{2*3}=\frac{48}{6}
=8
$