21=x^2+1

Solution for 21=x^2+1 equation:

Simplifying
21 = x2 + 1

Reorder the terms:
21 = 1 + x2

Solving
21 = 1 + x2

Solving for variable 'x'.

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

Add '-1x2' to each side of the equation.
21 + -1x2 = 1 + x2 + -1x2

Combine like terms: x2 + -1x2 = 0
21 + -1x2 = 1 + 0
21 + -1x2 = 1

Add '-21' to each side of the equation.
21 + -21 + -1x2 = 1 + -21

Combine like terms: 21 + -21 = 0
0 + -1x2 = 1 + -21
-1x2 = 1 + -21

Combine like terms: 1 + -21 = -20
-1x2 = -20

Divide each side by '-1'.
x2 = 20

Simplifying
x2 = 20

Take the square root of each side:
x = {-4.472135955, 4.472135955}