0.4x^2=2x^2-8.6

Solution for 0.4x^2=2x^2-8.6 equation:

Simplifying
0.4x2 = 2x2 + -8.6

Reorder the terms:
0.4x2 = -8.6 + 2x2

Solving
0.4x2 = -8.6 + 2x2

Solving for variable 'x'.

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

Add '-2x2' to each side of the equation.
0.4x2 + -2x2 = -8.6 + 2x2 + -2x2

Combine like terms: 0.4x2 + -2x2 = -1.6x2
-1.6x2 = -8.6 + 2x2 + -2x2

Combine like terms: 2x2 + -2x2 = 0
-1.6x2 = -8.6 + 0
-1.6x2 = -8.6

Divide each side by '-1.6'.
x2 = 5.375

Simplifying
x2 = 5.375

Take the square root of each side:
x = {-2.318404624, 2.318404624}