2(3x^2+4x-156)=0

Solution for 2(3x^2+4x-156)=0 equation:

2(3x^2+4x-156)=0

We multiply parentheses

6x^2+8x-312=0

a = 6; b = 8; c = -312;
Δ = b2-4ac
Δ = 82-4·6·(-312)
Δ = 7552
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:

$\sqrt{\Delta}=\sqrt{7552}=\sqrt{64*118}=\sqrt{64}*\sqrt{118}=8\sqrt{118}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-8\sqrt{118}}{2*6}=\frac{-8-8\sqrt{118}}{12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+8\sqrt{118}}{2*6}=\frac{-8+8\sqrt{118}}{12}
$