18=.5x^2

Solution for 18=.5x^2 equation:

Simplifying
18 = 0.5x2

Solving
18 = 0.5x2

Solving for variable 'x'.

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

Add '-0.5x2' to each side of the equation.
18 + -0.5x2 = 0.5x2 + -0.5x2

Combine like terms: 0.5x2 + -0.5x2 = 0.0
18 + -0.5x2 = 0.0

Add '-18' to each side of the equation.
18 + -18 + -0.5x2 = 0.0 + -18

Combine like terms: 18 + -18 = 0
0 + -0.5x2 = 0.0 + -18
-0.5x2 = 0.0 + -18

Combine like terms: 0.0 + -18 = -18
-0.5x2 = -18

Divide each side by '-0.5'.
x2 = 36

Simplifying
x2 = 36

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