-4x(3-2x)=12

Solution for -4x(3-2x)=12 equation:

-4x(3-2x)=12

We move all terms to the left:

-4x(3-2x)-(12)=0

We add all the numbers together, and all the variables

-4x(-2x+3)-12=0

We multiply parentheses

8x^2-12x-12=0

a = 8; b = -12; c = -12;
Δ = b2-4ac
Δ = -122-4·8·(-12)
Δ = 528
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:

$\sqrt{\Delta}=\sqrt{528}=\sqrt{16*33}=\sqrt{16}*\sqrt{33}=4\sqrt{33}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-4\sqrt{33}}{2*8}=\frac{12-4\sqrt{33}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+4\sqrt{33}}{2*8}=\frac{12+4\sqrt{33}}{16}
$