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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,529

A (rather too short) page on the Difference of Two Cubes

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 81,382

Hi MathsisFun;

It does some nifty expansions like:

calling a= 5x and b =2

So numbers like 15617 which equal 25^3 - 2^3 can be factored but not always into primes.

15617 = (23)(679)

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

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