x^2+x^2-3=9

Solution for x^2+x^2-3=9 equation:

Simplifying
x2 + x2 + -3 = 9

Reorder the terms:
-3 + x2 + x2 = 9

Combine like terms: x2 + x2 = 2x2
-3 + 2x2 = 9

Solving
-3 + 2x2 = 9

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 = 9 + 3

Combine like terms: -3 + 3 = 0
0 + 2x2 = 9 + 3
2x2 = 9 + 3

Combine like terms: 9 + 3 = 12
2x2 = 12

Divide each side by '2'.
x2 = 6

Simplifying
x2 = 6

Take the square root of each side:
x = {-2.449489743, 2.449489743}