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suma si diferenta de cuburi
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suma si diferenta de cuburi
Posted:
Sun Apr 19, 2009 10:53 am
by
Andi Brojbeanu
Demonstrati ca numarul
\( (1+2)^3+(3+4)^3+.......+(2n-1+2n)^3-1^3-2^3-3^3-4^3-.....-(2n-1)^3-(2n)^3 \)
este multiplu de 18 pentru orice
\( n\in \mathb{N}^* \)
.