180=x(1.25x)

Solution for 180=x(1.25x) equation:

Simplifying
180 = x(1.25x)

Remove parenthesis around (1.25x)
180 = x * 1.25x

Reorder the terms for easier multiplication:
180 = 1.25x * x

Multiply x * x
180 = 1.25x2

Solving
180 = 1.25x2

Solving for variable 'x'.

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

Add '-1.25x2' to each side of the equation.
180 + -1.25x2 = 1.25x2 + -1.25x2

Combine like terms: 1.25x2 + -1.25x2 = 0.00
180 + -1.25x2 = 0.00

Add '-180' to each side of the equation.
180 + -180 + -1.25x2 = 0.00 + -180

Combine like terms: 180 + -180 = 0
0 + -1.25x2 = 0.00 + -180
-1.25x2 = 0.00 + -180

Combine like terms: 0.00 + -180 = -180
-1.25x2 = -180

Divide each side by '-1.25'.
x2 = 144

Simplifying
x2 = 144

Take the square root of each side:
x = {-12, 12}