x^2+18-81=0

Solution for x^2+18-81=0 equation:

Simplifying
x2 + 18 + -81 = 0

Reorder the terms:
18 + -81 + x2 = 0

Combine like terms: 18 + -81 = -63
-63 + x2 = 0

Solving
-63 + x2 = 0

Solving for variable 'x'.

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

Add '63' to each side of the equation.
-63 + 63 + x2 = 0 + 63

Combine like terms: -63 + 63 = 0
0 + x2 = 0 + 63
x2 = 0 + 63

Combine like terms: 0 + 63 = 63
x2 = 63

Simplifying
x2 = 63

Take the square root of each side:
x = {-7.937253933, 7.937253933}