72=.5*x*4x

Solution for 72=.5*x*4x equation:

Simplifying
72 = 0.5x * 4x

Reorder the terms for easier multiplication:
72 = 0.5 * 4x * x

Multiply 0.5 * 4
72 = 2x * x

Multiply x * x
72 = 2x2

Solving
72 = 2x2

Solving for variable 'x'.

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

Add '-2x2' to each side of the equation.
72 + -2x2 = 2x2 + -2x2

Combine like terms: 2x2 + -2x2 = 0
72 + -2x2 = 0

Add '-72' to each side of the equation.
72 + -72 + -2x2 = 0 + -72

Combine like terms: 72 + -72 = 0
0 + -2x2 = 0 + -72
-2x2 = 0 + -72

Combine like terms: 0 + -72 = -72
-2x2 = -72

Divide each side by '-2'.
x2 = 36

Simplifying
x2 = 36

Take the square root of each side:
x = {-6, 6}