12x^2+66x-240=0

Solution for 12x^2+66x-240=0 equation:

12x^2+66x-240=0

a = 12; b = 66; c = -240;
Δ = b2-4ac
Δ = 662-4·12·(-240)
Δ = 15876
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{15876}=126$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(66)-126}{2*12}=\frac{-192}{24}
=-8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(66)+126}{2*12}=\frac{60}{24}
=2+1/2
$