15m^2-8m-12=0

Solution for 15m^2-8m-12=0 equation:

15m^2-8m-12=0

a = 15; b = -8; c = -12;
Δ = b2-4ac
Δ = -82-4·15·(-12)
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-28}{2*15}=\frac{-20}{30}
=-2/3
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+28}{2*15}=\frac{36}{30}
=1+1/5
$