here's a real tough one ( at least for me) ....show that the ring Z/mnZ where m ,n are relatively prime has an idempotent element other than 0 and 1.(adsbygoogle = window.adsbygoogle || []).push({});

i looked at examples and it works....

do we look for solutions of the equation a^2 -a = kmn , for some k in Z( that is, other than 0 and 1)?

help!

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# Idempotent elements

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