-12x^2+9x+156=0

Solution for -12x^2+9x+156=0 equation:

-12x^2+9x+156=0

a = -12; b = 9; c = +156;
Δ = b2-4ac
Δ = 92-4·(-12)·156
Δ = 7569
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7569}=87$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-87}{2*-12}=\frac{-96}{-24}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+87}{2*-12}=\frac{78}{-24}
=-3+1/4
$