Question:(Abstract algebra) Let G be a group and let H and K be subgroups
of G...
Question
(Abstract algebra) Let G be a group and let H and K be subgroups
of G...
(Abstract algebra) Let G be a group and let H and K be subgroups
of G so that H is not contained in K and K is not contained in H.
Prove that H ∪ K is not a subgroup of G.