Homework Statement
We've shown if G_{1},G_{2},...,G_{n} are subgroups of G s.t.
1)G_{1},G_{2},...,G_{n} are all normal
2)Every element of G can be written as g_{1}g_{2}...g_{n} with g_{i}\inG
3)For 1\leqi\leqn, G_{i}\capG_{1},G_{2},...,G_{i-1}=e
then G\congG_{1}xG_{2}x...xG_{n}...