First, we need to simplify the given expression:

1 3/7(1 2/5x - 3 1/2) + 0.7(5x - 3) = 9.4

To simplify the expression, we need to convert the mixed numbers to improper fractions:

1 3/7 = (71 + 3)/7 = 10/7
1 2/5 = (51 + 2)/5 = 7/5
3 1/2 = (2*3 + 1)/2 = 7/2

Now we substitute the values into the expression:

10/7(7/5x - 7/2) + 0.7(5x - 3) = 9.4

Next, we simplify the expression:

(10/7 (7/5)x - 10/7 7/2) + (0.7 5x - 0.7 3) = 9.4
(2x - 5) + (3.5x - 2.1) = 9.4
2x - 5 + 3.5x - 2.1 = 9.4
5.5x - 7.1 = 9.4
5.5x = 16.5
x = 3

Therefore, the value of x that satisfies the equation is 3.