Assume H and K are normal subgroups of G with the intersection of H and K is equal to 1. Prove xy = yx for every x in H and y in K. (That is, to show is in the intersection of H and K)
Assume H and K are normal subgroups of G with the intersection of H and K is equal to 1. Prove xy = yx for every x in H and y in K. (That is, to show is in the intersection of H and K)