Answer Abstract Algebra Questions - LCM & Subgroups

[uob_student]

hello

i have two questions and i need answers for them

first one:

in the additive group (Z,+)
show that nZ intersection mZ= lZ

, where l is the least common multiple of m and n.



The second question is :

Given H and K two subgroups of a group G , show the following:

(H union K) subgroup of G if and only if H subset of K or K subset of H

 

[uob_student]

i need the answers quickly

 

[matt grime]

Post them in the correct place and you might get some answers. Try the homework forum, or the maths forum, not this one.

Plus, saying things like 'i need the answers quickly' indicates this is for a homework assignment. You won't just be given the answers, this isn't a place where you get your homework done, so bear that in mind,