4x^2+1=21

Solution for 4x^2+1=21 equation:

Simplifying
4x2 + 1 = 21

Reorder the terms:
1 + 4x2 = 21

Solving
1 + 4x2 = 21

Solving for variable 'x'.

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

Add '-1' to each side of the equation.
1 + -1 + 4x2 = 21 + -1

Combine like terms: 1 + -1 = 0
0 + 4x2 = 21 + -1
4x2 = 21 + -1

Combine like terms: 21 + -1 = 20
4x2 = 20

Divide each side by '4'.
x2 = 5

Simplifying
x2 = 5

Take the square root of each side:
x = {-2.236067978, 2.236067978}