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https://mateforum.ro/viewtopic.php?t=2708
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Sir recurent
Posted:
Tue Nov 11, 2008 9:49 pm
by
alex2008
Stiind ca
\( 6a_1=12a_2=20a_3= ... =(n+1)(n+2)a_n \)
,
\( a_1+a_2+a_3+...+a_n=5760 \)
si
\( a_{n-1}-a_n=40 \)
, sa se afle
\( n \)
si termenii
\( a_1 \)
si
\( a_8 \)
.
Posted:
Mon Apr 20, 2009 6:26 pm
by
Andi Brojbeanu
Esti sigur ca enuntul e corect?