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Math Help - Sum=0

  1. #1
    Senior Member MaxJasper's Avatar
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    Question Sum=0

    Find values of natural numbers n, 0<n<100 for which appropriate selection of +/- signs makes the following equality true:

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  2. #2
    MHF Contributor
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    Re: Sum=0

    I'll start this thing: n = 20
    cubes of(1,2,5,6,16,17,18,19) = 22050 ; sum cubes (n=20) = 44100

    Sum of n cubes must be even, of course.
    So these n's are possibles:
    3,4 : 7,8 : 11,12 : ......... : 95,96 : 99,100
    Kick these out:
    1,2 : 5,6 : 9,10 : ...........: 93,94 : 97,98

    Your turn, Plato
    Last edited by Wilmer; September 20th 2012 at 09:49 AM.
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