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There is some formula that I can't precisely remember for polynomials, which goes something like $x^n-1 = (x-1)(\text{a lot of stuff})$. It could be more general, like $x^n - k$, or maybe it is just for the same powers, so $x^m - k^m$, but I think it's not just for the same powers. Does anyone know what I am talking about? I realize this is vague.

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    [Is this it](http://en.wikipedia.org/wiki/Factorization#Sum.2Fdifference_of_two_nth_powers) ???2012-02-21
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    The "stuff" is $x^{n-1}+x^{n-2}+\cdots+x+1$. A similar formula is applicable in the case $x^n-y^n$. But if the powers are *different*, you will not get anything so simple.2012-02-21
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    @JavaMan: Too late!2012-02-21
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    @jhgu Let me know if you understand my equations, or if further explanations are needed.2012-02-21

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