All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math
Dozen Divisibility Dilemma (Posted on 2010-12-02) Difficulty: 3 of 5
Each of x and y is a positive integer such that: x2 5y2 = 1.

Prove that x*y is always divisible by 12.

No Solution Yet Submitted by K Sengupta    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
re(2): Possible solution Comment 4 of 4 |
(In reply to re: Possible solution by Harry)


I wasn't sure if the extra step was needed. Indeed the stronger solve integer 4n-5y^2=1 also produces no integer solutions; I'll add something to my earlier post to round off the proof.

Edited on December 4, 2010, 12:31 am
  Posted by broll on 2010-12-04 00:15:06

Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (3)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2019 by Animus Pactum Consulting. All rights reserved. Privacy Information