-12m^2+80m+400=0

Solution for -12m^2+80m+400=0 equation:

-12m^2+80m+400=0

a = -12; b = 80; c = +400;
Δ = b2-4ac
Δ = 802-4·(-12)·400
Δ = 25600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25600}=160$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(80)-160}{2*-12}=\frac{-240}{-24}
=+10
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(80)+160}{2*-12}=\frac{80}{-24}
=-3+1/3
$