Subgroups - If K is a subgroup of H and H is a subgroup of G, is K a subgroup of G? Please justify your answer.
Subgroups - If X is a nonempty subset of a group G,
let ={x1^(k1),x2^(k2)...xm^(km)|m>=1, xiEX and kiEZ for each i}.
a) show that is a subgroup of G that contains x.
b) show that C=H for every subgro ...