To add and subtract fractions, we need to find a common denominator. In this case, the common denominator is 9*7*13=819.

So, the expression becomes:

(5/9)*91/91 + (7/8)*102/102 - (5/13)*63/63

Now, we can add and subtract the fractions:

455/819 + 714/819 - 315/819

= (455 + 714 - 315) / 819

= 854/819

= 854/819

Therefore, the simplified answer is 854/819.