1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Proof on the divisibility of integers

  1. Feb 16, 2010 #1
    1. The problem statement, all variables and given/known data

    Let a,b be integers where a doesn't =0. Prove that if a divides b, and b divides a, then a=b or a=-b


    3. The attempt at a solution

    I started out with b=aj and a=bk, where j,k are integers. Don't quite know how to proceed
     
  2. jcsd
  3. Feb 16, 2010 #2

    Mark44

    Staff: Mentor

    Substitute the expression for a or b into the other equation. What do you get?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook