10=x(1.6x)

Solution for 10=x(1.6x) equation:

Simplifying
10 = x(1.6x)

Remove parenthesis around (1.6x)
10 = x * 1.6x

Reorder the terms for easier multiplication:
10 = 1.6x * x

Multiply x * x
10 = 1.6x2

Solving
10 = 1.6x2

Solving for variable 'x'.

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

Add '-1.6x2' to each side of the equation.
10 + -1.6x2 = 1.6x2 + -1.6x2

Combine like terms: 1.6x2 + -1.6x2 = 0.0
10 + -1.6x2 = 0.0

Add '-10' to each side of the equation.
10 + -10 + -1.6x2 = 0.0 + -10

Combine like terms: 10 + -10 = 0
0 + -1.6x2 = 0.0 + -10
-1.6x2 = 0.0 + -10

Combine like terms: 0.0 + -10 = -10
-1.6x2 = -10

Divide each side by '-1.6'.
x2 = 6.25

Simplifying
x2 = 6.25

Take the square root of each side:
x = {-2.5, 2.5}