-12x^2-4x+56=0

Solution for -12x^2-4x+56=0 equation:

-12x^2-4x+56=0

a = -12; b = -4; c = +56;
Δ = b2-4ac
Δ = -42-4·(-12)·56
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-52}{2*-12}=\frac{-48}{-24}
=+2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+52}{2*-12}=\frac{56}{-24}
=-2+1/3
$