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Summing Series

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    Hi its me again, I'm having trouble with the following question.
    Find the sum of the series r^2(1+r), for the values r=n to r=2n. I keep getting, 1/12n(n+1)(45n^2+25n+2). Is this correct? apparently its... 1/12n(n+1)(45n^2+37n+2), any help would be appreciated since I'm not quite sure where I'm going wrong thanks in advance!
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    (Original post by mathssgeek)
    Hi its me again, I'm having trouble with the following question.
    Find the sum of the series r^2(1+r), for the values r=n to r=2n. I keep getting, 1/12n(n+1)(45n^2+25n+2). Is this correct? apparently its... 1/12n(n+1)(45n^2+37n+2), any help would be appreciated since I'm not quite sure where I'm going wrong thanks in advance!
    If you could post a picture of your working that will be helpful

    It looks like you went down the right path and then something went wrong (the given answer could always be wrong...)
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    (Original post by SeanFM)
    If you could post a picture of your working that will be helpful

    It looks like you went down the right path and then something went wrong (the given answer could always be wrong...)
    Thanks but no worries figured out wt i did wrong
 
 
 
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