To solve this equation, we need to first simplify both sides of the equation:

1.4/0.14 = 3.5/(0.1x+0.02)

10/1 = 3.5/(0.1x+0.02)

Now, cross multiply to solve for x:

10(0.1x + 0.02) = 3.5

1x + 0.2 = 3.5

1x = 3.3

x = 3.3

Therefore, the solution to the equation is x = 3.3.