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

Home > Just Math
Quadratic and Perfect Square Query II (Posted on 2016-05-21) Difficulty: 3 of 5
Determine all possible values of a positive integer N such that:
N2 + 72N is a perfect square.

No Solution Yet Submitted by K Sengupta    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Possible solution Comment 1 of 1
72N should have the form 2aN+a^2, with 0<a<36. 

This lead to N=a^2/(72-2a)
With integers for N=3,9,24,49,75,128,289, 

And the squares are: 15,27,48,77,105,160,323.

  Posted by armando on 2016-05-21 10:15:17
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 (4)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information