2x^2-3=21

Solution for 2x^2-3=21 equation:

Simplifying
2x2 + -3 = 21

Reorder the terms:
-3 + 2x2 = 21

Solving
-3 + 2x2 = 21

Solving for variable 'x'.

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

Add '3' to each side of the equation.
-3 + 3 + 2x2 = 21 + 3

Combine like terms: -3 + 3 = 0
0 + 2x2 = 21 + 3
2x2 = 21 + 3

Combine like terms: 21 + 3 = 24
2x2 = 24

Divide each side by '2'.
x2 = 12

Simplifying
x2 = 12

Take the square root of each side:
x = {-3.464101615, 3.464101615}