40.5=0.5*x*x

Solution for 40.5=0.5*x*x equation:

Simplifying
40.5 = 0.5x * x

Multiply x * x
40.5 = 0.5x2

Solving
40.5 = 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.
40.5 + -0.5x2 = 0.5x2 + -0.5x2

Combine like terms: 0.5x2 + -0.5x2 = 0.0
40.5 + -0.5x2 = 0.0

Add '-40.5' to each side of the equation.
40.5 + -40.5 + -0.5x2 = 0.0 + -40.5

Combine like terms: 40.5 + -40.5 = 0.0
0.0 + -0.5x2 = 0.0 + -40.5
-0.5x2 = 0.0 + -40.5

Combine like terms: 0.0 + -40.5 = -40.5
-0.5x2 = -40.5

Divide each side by '-0.5'.
x2 = 81

Simplifying
x2 = 81

Take the square root of each side:
x = {-9, 9}