12m^2-8m-64=0

Solution for 12m^2-8m-64=0 equation:

12m^2-8m-64=0

a = 12; b = -8; c = -64;
Δ = b2-4ac
Δ = -82-4·12·(-64)
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-56}{2*12}=\frac{-48}{24}
=-2
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+56}{2*12}=\frac{64}{24}
=2+2/3
$