To simplify this expression, we first need to find a common denominator for the fractions involved:

1/6 = 7/42
5/9 = 21/42
1/2 = 21/42
3/7 = 18/42
7 1/5 = 36/5

Now the expression becomes:

(7/42 - 21/42) (21/42 - 18/42) (36/5)

Simplify further:

(-14/42) (3/42) (36/5)

(-1/3) (1/14) (36/5)

(-1/3) * (36/70)

-36/210

-6/35

Therefore, (1/6 - 5/9) (1/2 - 3/7) 7 1/5 = -6/35