Question

Pe buneee?
Iar m-am blocat. :
$x( 1+\frac{1}{2}+ \frac{1}{3}+ \frac{1}{4}+...+ \frac{1}{2015})=2015- \frac{1}{2}- \frac{1}{2}- \frac{3}{4}-...- \frac{2014}{2015}$
Deci,....

Answer 1

lucram in partea drepata a semnului egal. PE 2015 il scrie. ca suma de 1+1+1.....+1. apoi grpam termenii cate 2. => 1+(1-1/2)+(1-2/3)+(1-3/4)+.....(1-2014/2015)=1+1/2+1/3+1/4+.....1/2015). exercitiul nostru arata cam asa.x(1+1/2+1/3+1/4+...1/2015)=1+1/2+1/3+1/4+....1/2015=> x=1