Vì \(\frac{2000}{2001}< \frac{2003}{2002}\) do \(\frac{2000}{2001}< 0< \frac{2003}{2003}\) (tử lớn hơn mẫu) nên khi là số nguyên âm \(\frac{2000}{-2001}>\frac{-2003}{2002}\)

ta có\(\dfrac{2001}{2002}< 1\)và\(\dfrac{2005}{2003}>1\)

\(\Rightarrow\dfrac{2001}{2002}< \dfrac{2005}{2003}\)

ta có:\(A=\frac{2000}{2001}+\frac{2001}{2002}<\frac{2000}{2002}+\frac{2001}{2002}=\frac{2000+2001}{2002}<\frac{2000+2001}{2001+2002}=B\)

\(\Rightarrow A

ta có:\(B=\frac{2000+2001}{2001+2002}=\frac{2000}{2001+2002}+\frac{2001}{2001+2002}\)

vì \(\frac{2000}{2001}>\frac{2000}{2001+2002}và\frac{2001}{2002}>\frac{2001}{2001+2002}\)

\(\Rightarrow\frac{2000}{2001}+\frac{2001}{2002}>\frac{2000+2001}{2001+2002}\)

=>A>B

B=2000+1+2002=4003

A=2000/2001+2001/2002

=2002.(2000+2001)/2001.2002

=2000+2001/2001<1

Mà B>1 suy ra A<B

Ta có 

B= 2000/2001+2002 + 2001/2001+2002.                                                           Mà 2000/2001+2002 < 2000/2001 và 2001/2001+2002 < 2001/2002.              Nên 2000/2001+2002 + 2001/ 2001+2002 < 2000/2001 + 2001/2002.       Hay 2000+2001/ 2001+2002 < 2000/2001 + 2001/2002                             Suy ra B < A

A>B

CÁC BẠN NHỚ **** CHO MÌNH NHA

•  13/27 và 7/15
  \(\frac{13}{27}\) = 1:\(\frac{27}{13}\)= 1: \(\frac{26+1}{13}\) = 1: ( 2+\(\frac{1}{13}\))
  \(\frac{7}{15}\)= 1:\(\frac{15}{7}\)= 1: \(\frac{14+1}{7}\)= 1: ( 2+ \(\frac{1}{7}\))
  ta có \(\frac{1}{13}\)< \(\frac{1}{7}\)=>   2+\(\frac{1}{13}\)< 2+ \(\frac{1}{7}\) => 1: ( 2+\(\frac{1}{13}\)) >  1: ( 2+ \(\frac{1}{7}\))
  
  vậy \(\frac{13}{27}\)>\(\frac{7}{15}\)

•  2000/2001 và 2001/2002
  \(\frac{2000}{2001}\)= \(\frac{2001-1}{2001}\)= 1 - \(\frac{1}{2001}\)
  \(\frac{2001}{2002}\)= \(\frac{2002-1}{2002}\)= 1 - \(\frac{1}{2002}\)
  ta có \(\frac{1}{2001}\)> \(\frac{1}{2002}\) =>  1 - \(\frac{1}{2001}\) <  1 - \(\frac{1}{2002}\)
  vậy  \(\frac{2000}{2001}\)< \(\frac{2001}{2002}\)

\(\frac{2000}{2001}=1-\frac{1}{2001}\)

\(\frac{2001}{2002}=1-\frac{1}{2002}\)

\(2001< 2002\Rightarrow\frac{1}{2001}>\frac{1}{2001}\)

                             \(\Rightarrow1-\frac{1}{2001}< 1-\frac{1}{2002}\)

                              \(\Rightarrow\frac{2000}{2001}< \frac{2001}{2002}\)

ta có:2000/2001=1-1/2001

2001/2002=1-1/2002

mà 2001<2002

suy ra 1/2001>1/2002

suy ra 1-1/2001<1-1/2002

vậy 2000/2001<2001/2002

Ta có 

B= 2000/2001+2002 + 2001/2001+2002.                                                          

Mà 2000/2001+2002 < 2000/2001 và 2001/2001+2002 < 2001/2002.              

Nên 2000/2001+2002 + 2001/ 2001+2002 < 2000/2001 + 2001/2002.      

Hay 2000+2001/ 2001+2002 < 2000/2001 + 2001/2002                            

Suy ra B < A

Ta có : 2000/2001 > 2000/ 2001 + 2002 (1)

2001/2002 > 2001/2001+2002(2)

Cộng các bất đẳng thức (1) và (2)  vế với nhau:

Vậy 2000/2001 + 2001/2002> 2000/2001+2002 hay A > B