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Homework Help: Induction - number theory

  1. Feb 21, 2010 #1
    1. The problem statement, all variables and given/known data

    Show 7 divides 3^(2n+1) + 2^(n+2)

    3. The attempt at a solution

    Have proved base case K=1 and for the case k+1 I have got ot the point of trying to show 7 divides 9.3^(2k+1) + 2.2^(k+2).

    Any pointers would be much appreciated. Thanks in advance
     
  2. jcsd
  3. Feb 21, 2010 #2

    Hurkyl

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    Well, you don't seem to have even stated the inductive hypothesis yet, let alone tried doing something with it.
     
  4. Feb 21, 2010 #3
    The inductive hypothesis is that 7 divides 3^(2k+1) + 2^(k+2)
     
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