Question

Cho A=1/2+1/3+1/4+...+1/2011+1/2012

B=2011/1+2010/2+2009/3+...+2/2010+1/2011

Tính A/B

Answer 1

Ta có \(B=\left(\frac{2010}{2}+1\right)+\left(\frac{2009}{3}+1\right)+...+\left(\frac{2}{2010}+1\right)+\left(\frac{1}{2011}+1\right)+1\)

\(B=\frac{2012}{2}+\frac{2012}{3}+...+\frac{2012}{2010}+\frac{2012}{2011}+\frac{2012}{2012}\)

\(B=2012.\left(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}\right)\)

B=2012.A

=>A/B=1/2012

Answer 2

a/b= 1/2012 nha bạn 

tích

Answer 3

bạn ơi tính A đi bạn

Answer 4

2011/1 dau ban

Answer 5

Hải Ngân ơi k cái cc

Answer 6

1/2+1/3+1/4+...+1/2011+1/201

2011/1+2010/2+2009/3+...+2/2010+1/201

=1/2=1/2+1/4+...+1/2012

2011+2010/2+2009/3+...+2/2010+1/2011

roi lam nhu ban nguyen tuan minh con ve tren giu nguyen