-4(6x^2+4x-14)=0

Solution for -4(6x^2+4x-14)=0 equation:

-4(6x^2+4x-14)=0

We multiply parentheses

-24x^2-16x+56=0

a = -24; b = -16; c = +56;
Δ = b2-4ac
Δ = -162-4·(-24)·56
Δ = 5632
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:

$\sqrt{\Delta}=\sqrt{5632}=\sqrt{256*22}=\sqrt{256}*\sqrt{22}=16\sqrt{22}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-16\sqrt{22}}{2*-24}=\frac{16-16\sqrt{22}}{-48}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+16\sqrt{22}}{2*-24}=\frac{16+16\sqrt{22}}{-48}
$