-x^2+225=0

Solution for -x^2+225=0 equation:

Simplifying
-1x2 + 225 = 0

Reorder the terms:
225 + -1x2 = 0

Solving
225 + -1x2 = 0

Solving for variable 'x'.

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

Add '-225' to each side of the equation.
225 + -225 + -1x2 = 0 + -225

Combine like terms: 225 + -225 = 0
0 + -1x2 = 0 + -225
-1x2 = 0 + -225

Combine like terms: 0 + -225 = -225
-1x2 = -225

Divide each side by '-1'.
x2 = 225

Simplifying
x2 = 225

Take the square root of each side:
x = {-15, 15}