Prime Division HELP

  • #1
Prime Division HELP!!!

Homework Statement



I need to be able to understand and likely prove that for any positive odd integer n,
8 | (n^2 -1 )

Homework Equations





The Attempt at a Solution


odd can be said to be n = 2k +1
so 8 | (2k + 1)^2 -1
 

Answers and Replies

  • #2
phyzguy
Science Advisor
4,740
1,670


Keep going. Now expand out (2k+1)^2 - 1 and collect terms. Then think about the terms in k and k+1.
 
  • #3


I got stumped trying mathematical induction i was hoping for a new approach
 
  • #4
34,675
6,386


Try the approach that phyzguy is suggesting.
 

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