Question

Puteti sa ma ajutati.Unde e incercuit.

Answer 1

membrul  stang  se  mai  scrie
(1-1/2)+(1/2-1/3)+(1/3-1/4)+...+(1/x-1/(x+1))=2010/2011
desfaci  parantezele si  reduci  termenii  opusi
1-1/2+1/2-1/3+1/3-1/4+...+1/x-1/(x+1)=2010/2011
1-1/(x+1)=2010/2011
(x+1-1)/(x+1)=2010/2011
x/(x+1)=2010/2011 =>
x=2010

Answer 2

(1-1/2)+(1/2-1/3)+(1/3-1/4)+...+(1/x-1/(x+1))=2010/2011

1-1/2+1/2-1/3+1/3-1/4+...+1/x-1/(x+1)=2010/2011
1-1/(x+1)=2010/2011
(x+1-1)/(x+1)=2010/2011
x/(x+1)=2010/2011 =>
x=2010