x^2+2x^2-40=0

Solution for x^2+2x^2-40=0 equation:

Simplifying
x2 + 2x2 + -40 = 0

Reorder the terms:
-40 + x2 + 2x2 = 0

Combine like terms: x2 + 2x2 = 3x2
-40 + 3x2 = 0

Solving
-40 + 3x2 = 0

Solving for variable 'x'.

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

Add '40' to each side of the equation.
-40 + 40 + 3x2 = 0 + 40

Combine like terms: -40 + 40 = 0
0 + 3x2 = 0 + 40
3x2 = 0 + 40

Combine like terms: 0 + 40 = 40
3x2 = 40

Divide each side by '3'.
x2 = 13.33333333

Simplifying
x2 = 13.33333333

Take the square root of each side:
x = {-3.651483716, 3.651483716}