Show subgroups of an abelian group isomorphic to each other
108213
$N_1,N_2,N_3 \unlhd G, N_i\cap N_j =\{e\}, G = N_iN_j$. Want to show that $G$ is abelian, $N_i$ are isomorphic.
83001
Easier way to show $(\mathbb{Z}/(n))[x]$ and $\mathbb{Z}[x] / (n)$ are isomorphic
49527
Prove that $a$ commutes with each of its conjugates in $G$ iff $a$ belongs to an abelian normal subgroup of $G$.
46263
Automorphisms of infinite abelian groups
112872
Involutions and Abelian Groups
41231
Subgroups of (Z,+) of order n
115204
Show that SO(n) is a normal subgroup of O(n)
72150
Union of the conjugates of a proper subgroup
74586
Prove that every group of order $4$ is abelian
6466
Image of subgroup and Kernel of homomorphism form subgroups
137896
Isomorphism equivalence implies fundamental group is abelian
25439
f(a) = inverse of a is an isomorphism iff a group G is Abelian
111168
Automorphisms of a finite non-abelian group
11003
Proving that $G/N$ is an abelian group
71035
Non abelian subgroup of a abelian group.
154398
Show that H is a subgroup of G
139835
Every Finite Group is Isomorphic to a Subgroup of $A_n$