x^2-21-100=0

Solution for x^2-21-100=0 equation:

Simplifying
x2 + -21 + -100 = 0

Reorder the terms:
-21 + -100 + x2 = 0

Combine like terms: -21 + -100 = -121
-121 + x2 = 0

Solving
-121 + x2 = 0

Solving for variable 'x'.

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

Add '121' to each side of the equation.
-121 + 121 + x2 = 0 + 121

Combine like terms: -121 + 121 = 0
0 + x2 = 0 + 121
x2 = 0 + 121

Combine like terms: 0 + 121 = 121
x2 = 121

Simplifying
x2 = 121

Take the square root of each side:
x = {-11, 11}