2x^2-1=15

Solution for 2x^2-1=15 equation:

Simplifying
2x2 + -1 = 15

Reorder the terms:
-1 + 2x2 = 15

Solving
-1 + 2x2 = 15

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 + 2x2 = 15 + 1

Combine like terms: -1 + 1 = 0
0 + 2x2 = 15 + 1
2x2 = 15 + 1

Combine like terms: 15 + 1 = 16
2x2 = 16

Divide each side by '2'.
x2 = 8

Simplifying
x2 = 8

Take the square root of each side:
x = {-2.828427125, 2.828427125}