900=0.15*x^2

Solution for 900=0.15*x^2 equation:

Simplifying
900 = 0.15x2

Solving
900 = 0.15x2

Solving for variable 'x'.

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

Add '-0.15x2' to each side of the equation.
900 + -0.15x2 = 0.15x2 + -0.15x2

Combine like terms: 0.15x2 + -0.15x2 = 0.00
900 + -0.15x2 = 0.00

Add '-900' to each side of the equation.
900 + -900 + -0.15x2 = 0.00 + -900

Combine like terms: 900 + -900 = 0
0 + -0.15x2 = 0.00 + -900
-0.15x2 = 0.00 + -900

Combine like terms: 0.00 + -900 = -900
-0.15x2 = -900

Divide each side by '-0.15'.
x2 = 6000

Simplifying
x2 = 6000

Take the square root of each side:
x = {-77.459666924, 77.459666924}