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
  • #2

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

Try the approach that phyzguy is suggesting.

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