x^2+2x^2-120=0

Solution for x^2+2x^2-120=0 equation:

Simplifying
x2 + 2x2 + -120 = 0

Reorder the terms:
-120 + x2 + 2x2 = 0

Combine like terms: x2 + 2x2 = 3x2
-120 + 3x2 = 0

Solving
-120 + 3x2 = 0

Solving for variable 'x'.

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

Add '120' to each side of the equation.
-120 + 120 + 3x2 = 0 + 120

Combine like terms: -120 + 120 = 0
0 + 3x2 = 0 + 120
3x2 = 0 + 120

Combine like terms: 0 + 120 = 120
3x2 = 120

Divide each side by '3'.
x2 = 40

Simplifying
x2 = 40

Take the square root of each side:
x = {-6.32455532, 6.32455532}