We can simplify the equation by combining like terms:

11.3x - (9.7x - 0.8x) + 7.4 = 17

First, simplify the expression inside the parentheses:

11.3x - 9.7x + 0.8x + 7.4 = 17

Now, combine like terms:

2.4x + 7.4 = 17

Subtract 7.4 from both sides:

2.4x = 9.6

Finally, divide by 2.4 to solve for x:

x = 4