To solve for x in the equation 2.4 + (3/5)x = (1 1/15)x + 1.56, we first need to simplify the fractions on the right side of the equation.

3/5x = 1/15x + 1.56

Next, we need to combine like terms by subtracting 1/15x from both sides:

3/5x - 1/15x = 1.56

Now, we have:

(9/15)x - (1/15)x = 1.56

(8/15)x = 1.56

To solve for x, we multiply both sides by 15/8:

x = 1.56 * (15/8)

x = 2.925

Therefore, the solution to the equation 2.4 + (3/5)x = (1 1/15)x + 1.56 is x = 2.925.