12x^2+84x-72=0

Solution for 12x^2+84x-72=0 equation:

12x^2+84x-72=0

a = 12; b = 84; c = -72;
Δ = b2-4ac
Δ = 842-4·12·(-72)
Δ = 10512
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{10512}=\sqrt{144*73}=\sqrt{144}*\sqrt{73}=12\sqrt{73}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(84)-12\sqrt{73}}{2*12}=\frac{-84-12\sqrt{73}}{24}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(84)+12\sqrt{73}}{2*12}=\frac{-84+12\sqrt{73}}{24}
$