12x^2+15x-153=0

Solution for 12x^2+15x-153=0 equation:

12x^2+15x-153=0

a = 12; b = 15; c = -153;
Δ = b2-4ac
Δ = 152-4·12·(-153)
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{-(15)-87}{2*12}=\frac{-102}{24}
=-4+1/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+87}{2*12}=\frac{72}{24}
=3
$