0=-0.2(3x^2)+12

Solution for 0=-0.2(3x^2)+12 equation:

Simplifying
0 = -0.2(3x2) + 12

Remove parenthesis around (3x2)
0 = -0.2 * 3x2 + 12

Multiply -0.2 * 3
0 = -0.6x2 + 12

Reorder the terms:
0 = 12 + -0.6x2

Solving
0 = 12 + -0.6x2

Solving for variable 'x'.

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

Add '0.6x2' to each side of the equation.
0 + 0.6x2 = 12 + -0.6x2 + 0.6x2
Remove the zero:
0.6x2 = 12 + -0.6x2 + 0.6x2

Combine like terms: -0.6x2 + 0.6x2 = 0.0
0.6x2 = 12 + 0.0
0.6x2 = 12

Divide each side by '0.6'.
x2 = 20

Simplifying
x2 = 20

Take the square root of each side:
x = {-4.472135955, 4.472135955}