-4(x+3)3x=14=

Solution for -4(x+3)3x=14= equation:

-4(x+3)3x=14=

We move all terms to the left:

-4(x+3)3x-(14)=0

We multiply parentheses

-12x^2-36x-14=0

a = -12; b = -36; c = -14;
Δ = b2-4ac
Δ = -362-4·(-12)·(-14)
Δ = 624
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:

$\sqrt{\Delta}=\sqrt{624}=\sqrt{16*39}=\sqrt{16}*\sqrt{39}=4\sqrt{39}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-4\sqrt{39}}{2*-12}=\frac{36-4\sqrt{39}}{-24}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+4\sqrt{39}}{2*-12}=\frac{36+4\sqrt{39}}{-24}
$