x(3x)-12=0

Solution for x(3x)-12=0 equation:

Simplifying
x(3x) + -12 = 0

Remove parenthesis around (3x)
x * 3x + -12 = 0

Reorder the terms for easier multiplication:
3x * x + -12 = 0

Multiply x * x
3x2 + -12 = 0

Reorder the terms:
-12 + 3x2 = 0

Solving
-12 + 3x2 = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '12' to each side of the equation.
-12 + 12 + 3x2 = 0 + 12

Combine like terms: -12 + 12 = 0
0 + 3x2 = 0 + 12
3x2 = 0 + 12

Combine like terms: 0 + 12 = 12
3x2 = 12

Divide each side by '3'.
x2 = 4

Simplifying
x2 = 4

Take the square root of each side:
x = {-2, 2}