12=.5x(x+(2x))

Solution for 12=.5x(x+(2x)) equation:

Simplifying
12 = 0.5x(x + (2x))

Combine like terms: x + (2x) = 3x
12 = 0.5x(3x)

Remove parenthesis around (3x)
12 = 0.5x * 3x

Reorder the terms for easier multiplication:
12 = 0.5 * 3x * x

Multiply 0.5 * 3
12 = 1.5x * x

Multiply x * x
12 = 1.5x2

Solving
12 = 1.5x2

Solving for variable 'x'.

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

Add '-1.5x2' to each side of the equation.
12 + -1.5x2 = 1.5x2 + -1.5x2

Combine like terms: 1.5x2 + -1.5x2 = 0.0
12 + -1.5x2 = 0.0

Add '-12' to each side of the equation.
12 + -12 + -1.5x2 = 0.0 + -12

Combine like terms: 12 + -12 = 0
0 + -1.5x2 = 0.0 + -12
-1.5x2 = 0.0 + -12

Combine like terms: 0.0 + -12 = -12
-1.5x2 = -12

Divide each side by '-1.5'.
x2 = 8

Simplifying
x2 = 8

Take the square root of each side:
x = {-2.828427125, 2.828427125}