Let M = S_1 coproduct S_2 .... coproduct S_n. be a direct sum of R-modules. If T_i is a subset of S_i for all i prove that
(S_1 coproduct .... coproduct S_n)/(T_1 coproduct ....T_n) is isomorphic to
(S_1/T_1) co product (S_2/T_2) ---- coproduct (S_n/T_n).