.5x^2-800=0

Solution for .5x^2-800=0 equation:

Simplifying
0.5x2 + -800 = 0

Reorder the terms:
-800 + 0.5x2 = 0

Solving
-800 + 0.5x2 = 0

Solving for variable 'x'.

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

Add '800' to each side of the equation.
-800 + 800 + 0.5x2 = 0 + 800

Combine like terms: -800 + 800 = 0
0 + 0.5x2 = 0 + 800
0.5x2 = 0 + 800

Combine like terms: 0 + 800 = 800
0.5x2 = 800

Divide each side by '0.5'.
x2 = 1600

Simplifying
x2 = 1600

Take the square root of each side:
x = {-40, 40}