12=4x(-6x-3)

Solution for 12=4x(-6x-3) equation:

Simplifying
12 = 4x(-6x + -3)

Reorder the terms:
12 = 4x(-3 + -6x)
12 = (-3 * 4x + -6x * 4x)
12 = (-12x + -24x2)

Solving
12 = -12x + -24x2

Solving for variable 'x'.

Reorder the terms:
12 + 12x + 24x2 = -12x + 12x + -24x2 + 24x2

Combine like terms: -12x + 12x = 0
12 + 12x + 24x2 = 0 + -24x2 + 24x2
12 + 12x + 24x2 = -24x2 + 24x2

Combine like terms: -24x2 + 24x2 = 0
12 + 12x + 24x2 = 0

Factor out the Greatest Common Factor (GCF), '12'.
12(1 + x + 2x2) = 0

Ignore the factor 12.
Subproblem 1
Set the factor '(1 + x + 2x2)' equal to zero and attempt to solve:

Simplifying
1 + x + 2x2 = 0

Solving
1 + x + 2x2 = 0

Begin completing the square.  Divide all terms by
2 the coefficient of the squared term: 

Divide each side by '2'.
0.5 + 0.5x + x2 = 0

Move the constant term to the right:

Add '-0.5' to each side of the equation.
0.5 + 0.5x + -0.5 + x2 = 0 + -0.5

Reorder the terms:
0.5 + -0.5 + 0.5x + x2 = 0 + -0.5

Combine like terms: 0.5 + -0.5 = 0.0
0.0 + 0.5x + x2 = 0 + -0.5
0.5x + x2 = 0 + -0.5

Combine like terms: 0 + -0.5 = -0.5
0.5x + x2 = -0.5

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
0.5x + 0.25 + x2 = -0.5 + 0.25

Reorder the terms:
0.25 + 0.5x + x2 = -0.5 + 0.25

Combine like terms: -0.5 + 0.25 = -0.25
0.25 + 0.5x + x2 = -0.25

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = -0.25

Can't calculate square root of the right side.

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.