Question About Relatively Prime

[zohapmkoftid]

1. The problem statement, all variables and given/known data

http://uploadpie.com/AkdSv

2. Relevant equations



3. The attempt at a solution

I have already done part (i) but I don't know how to use part (i) to prove (ii). Since they are relatively prime, so I write
http://uploadpie.com/vsDQk

But I don't know how to continue