0.2(x^2-10)=18

Solution for 0.2(x^2-10)=18 equation:

Simplifying
0.2(x2 + -10) = 18

Reorder the terms:
0.2(-10 + x2) = 18
(-10 * 0.2 + x2 * 0.2) = 18
(-2 + 0.2x2) = 18

Solving
-2 + 0.2x2 = 18

Solving for variable 'x'.

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

Add '2' to each side of the equation.
-2 + 2 + 0.2x2 = 18 + 2

Combine like terms: -2 + 2 = 0
0 + 0.2x2 = 18 + 2
0.2x2 = 18 + 2

Combine like terms: 18 + 2 = 20
0.2x2 = 20

Divide each side by '0.2'.
x2 = 100

Simplifying
x2 = 100

Take the square root of each side:
x = {-10, 10}