x^2+2x^2-900=0

Solution for x^2+2x^2-900=0 equation:

Simplifying
x2 + 2x2 + -900 = 0

Reorder the terms:
-900 + x2 + 2x2 = 0

Combine like terms: x2 + 2x2 = 3x2
-900 + 3x2 = 0

Solving
-900 + 3x2 = 0

Solving for variable 'x'.

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

Add '900' to each side of the equation.
-900 + 900 + 3x2 = 0 + 900

Combine like terms: -900 + 900 = 0
0 + 3x2 = 0 + 900
3x2 = 0 + 900

Combine like terms: 0 + 900 = 900
3x2 = 900

Divide each side by '3'.
x2 = 300

Simplifying
x2 = 300

Take the square root of each side:
x = {-17.320508076, 17.320508076}