(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I'm given the identity:

[tex]\sum{\frac{r^{3}-r+1}{r(r+1)} \equiv r-1 + \frac{1}{r} - \frac{1}{r+1}[/tex]

EDIT: from r=1 to n on the sum sign

2. Relevant equations

I know I'm ment to use the method of differences and I know that

[tex]\sum(r) = \frac{n(n+1)}{2}[/tex]

3. The attempt at a solution

I presume you need to find out how you can relate the 3 fractions to the summation of r?

Thanks :)

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# Homework Help: Method of Differences

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