Simplifying
x2 + -9 = 55
Reorder the terms:
-9 + x2 = 55
Solving
-9 + x2 = 55
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '9' to each side of the equation.
-9 + 9 + x2 = 55 + 9
Combine like terms: -9 + 9 = 0
0 + x2 = 55 + 9
x2 = 55 + 9
Combine like terms: 55 + 9 = 64
x2 = 64
Simplifying
x2 = 64
Take the square root of each side:
x = {-8, 8}