x^2+2x^2+20-40=180

Solution for x^2+2x^2+20-40=180 equation:

Simplifying
x2 + 2x2 + 20 + -40 = 180

Reorder the terms:
20 + -40 + x2 + 2x2 = 180

Combine like terms: 20 + -40 = -20
-20 + x2 + 2x2 = 180

Combine like terms: x2 + 2x2 = 3x2
-20 + 3x2 = 180

Solving
-20 + 3x2 = 180

Solving for variable 'x'.

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

Add '20' to each side of the equation.
-20 + 20 + 3x2 = 180 + 20

Combine like terms: -20 + 20 = 0
0 + 3x2 = 180 + 20
3x2 = 180 + 20

Combine like terms: 180 + 20 = 200
3x2 = 200

Divide each side by '3'.
x2 = 66.66666667

Simplifying
x2 = 66.66666667

Take the square root of each side:
x = {-8.164965809, 8.164965809}