x^2-3+x^2-3=66

Solution for x^2-3+x^2-3=66 equation:

Simplifying
x2 + -3 + x2 + -3 = 66

Reorder the terms:
-3 + -3 + x2 + x2 = 66

Combine like terms: -3 + -3 = -6
-6 + x2 + x2 = 66

Combine like terms: x2 + x2 = 2x2
-6 + 2x2 = 66

Solving
-6 + 2x2 = 66

Solving for variable 'x'.

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

Add '6' to each side of the equation.
-6 + 6 + 2x2 = 66 + 6

Combine like terms: -6 + 6 = 0
0 + 2x2 = 66 + 6
2x2 = 66 + 6

Combine like terms: 66 + 6 = 72
2x2 = 72

Divide each side by '2'.
x2 = 36

Simplifying
x2 = 36

Take the square root of each side:
x = {-6, 6}