a +b == Subscript[q,1]n + Subscript[r,1]
b + c == Subscript[q,2]n + Subscript[r,2]
Subscript[r,1] + c == Subscript[q, 3]n + Subscript[r,3]
Expand[a+b+c]
I want to get the result of a+b+c which should be (q1+q3)n + r3 (from 1 and 3). Is it possible to get this result evaluated automatically ? If so what command should i use , instead of Expand.