SOLUTION: Find all the orders of subroups of Z20? Hi The Best Teachers online! Can you help me on this question please? Thank you! God bless!

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Question 1137639: Find all the orders of subroups of Z20?
Hi The Best Teachers online! Can you help me on this question please? Thank you! God bless!

Answer by ikleyn(52775) About Me  (Show Source):
You can put this solution on YOUR website!
.

For any subgroup of a group, its order divides the order of the group.


So, we potentially have the orders of subgroups as 2, 4, 5 and 10  (all the divisors of the number 20).


Now, each of these numbers is really realized as the order of a subgroup.


For it, you should know that Z20 is the additive group of integers from 0 to 19 modulus 20.


Then the subgroup of the order 2 is the subgroup (the subset) {0,10} of Z20;

     the subgroup of the order 4 is the subgroup (the subset) {0,5,10,15} of Z20;

     the subgroup of the order 5 is the subgroup (the subset) {0,4,8,12,16} of Z20;

     the subgroup of the order 10 is the subgroup (the subset) {0,2,4,6,8,10,12,14,16,18} of Z20.

Completed, solved and explained.