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Homework Help: Cant get it correct!

  1. Nov 7, 2005 #1
    What is wrong with this proof? There seems to be a missing link at the n^4 term, even though values of n up to 134 are true!

  2. jcsd
  3. Nov 7, 2005 #2
    without seeing it all souldn't the answers to each line read as follows:



    n+11n+41n+61n+30n (if you add the two lines above together)
  4. Nov 7, 2005 #3


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    1. You haven't told us what you are trying to prove!

    2. What you posted makes no sense! In the last line, there appears to be no n on the left side, yet the right side depends on n.
  5. Nov 7, 2005 #4
    I am trying to preform a proof by induction that for any positive number n,

    1 x 2 x 3 x 4 + 2 x 3 x 4 x 5 + ...+ n (n+1)(n+2)(n+3)(n+4)

    = n^4 + 6n^3 + 11n^2 + 6n

    So in the image just consider the k as n.

    It's a polynomial with a pretty long expansion, but I have checked and rechecked and if there is an error, I cant find one. Yet it cant be proven?
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