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The Clock-Tower School Juniors Competion 2nd problem

Posted: Mon Mar 22, 2010 10:31 am
by salazar
Fie multimea \( S=\lbrace(x+y)^7-x^7-y^7|x,y\in Z\} \). Determinati cel mai mare divizor comun al numerelor din \( S \)

Posted: Mon Mar 22, 2010 1:38 pm
by Marius Mainea
\( 2\cdot 3\cdot 7 \)

Se foloseste teorema lui Fermat \( a^p\equiv a (mod p) \) daca p este prim.

Posted: Mon Mar 22, 2010 1:48 pm
by salazar
Marius Mainea wrote:\( 2\cdot 6\cdot 9 \)
de exemplu, pentru x=y=1 si x=1.y=2 c.m.m.d.c este 42