You should first make 7 3/7 and 3 3/5 into improper fractions that would be 52/7 and 18/5 then we can add but we have to make them equivelent in order to do so.
52/7 = 260/35
18/5 = 126/35
Add 260 and 126 and we will get 386/35 but remember we still have to make it a mixed number so we finally get the answer of 11 1/35