Prove that if A and B are subgroups of a group G, and A U B is also a subgroup, then A
Chapter 14, Problem 14.38(choose chapter or problem)
Prove that if A and B are subgroups of a group G, and A U B is also a subgroup, then A S; Bor A :2 B. (Compare 7.13 and Theorem 15.1.)
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