To solve this expression, we first need to simplify the multiplication in each fraction:

7/18 9/14 = 63/252
1/3 6/7 = 6/21

Now, we add these two simplified fractions together:

63/252 + 6/21

To add these fractions, we need to make sure they have a common denominator. The least common multiple of 252 and 21 is 252.

Rewriting the fractions with a common denominator:

63/252 + 6/252 = 69/252

Now, we simplify the fraction 69/252 by dividing the numerator and denominator by their greatest common factor, which is 3:

69 ÷ 3 = 23
252 ÷ 3 = 84

So, the final result of the expression 7/18 9/14 + 1/3 6/7 is 23/84.