đặt A=1919/2121=1919:101/2121:101=19/21

B=191919/212121=191919:10101/212121:10101=19/21

=>A=B=19/21

ai tra loi tui se k cho

tất cả phân số trên đều bằng nhau

a: 19191/2121<1<21/19

b: 62/51>1>56/45

1717/1919=17/19

171717/191919=17/19

Vậy  1717/1919 = 171717/191919

a) 1995/1996 và 1996/1997

 Ta có: 1995/1996=1 - 1/1996        

            1996/1997=1 - 1/1997

Vì 1/1996 > 1/1997 nên 1995/1996 < 1996/1997

b) Ta có: \(\frac{2121}{3737}=\frac{2121:101}{3737:101}=\frac{21}{37}\); \(\frac{212121}{373737}=\frac{212121:10101}{373737:10101}=\frac{21}{37}\)

Vì 21/37=21/37 nên 2121/3737 = 212121/373737

a, Ta có: 1-1995/1996=1/1996  ;  1-1996/1997=1/1997

do 1/1996 > 1/1997 nên 1995/1996 < 1996 1997

ai thấy đúng thì k cho mình nha

Ta có:1-1995/1996=1/1996

1-1996/1997=1/1997

Vì 1/1996>1/1997=>1995/1996<1996/1997

b, 2121/3737=2121/101=21

                       3737/101=37

212121/373737=212121/10101=21

                           373737/10101=37

=>2121/3737=212121/373737

a) \(\dfrac{1995}{1996}\) < \(\dfrac{1996}{1997}\)

b) \(\dfrac{2121}{3737}\) = \(\dfrac{212121}{373737}\)

giup ik mà :((
 

1717/2121=17/21

232323/191919=23/19

b : 2121/3737 = 212121/373737 

Vì 2121/3737  rút gọn thành 21/37

212121/373737 rút gọn thành 21/37 luôn

Mình chỉ biết làm câu b thôi

a)\(\frac{1995}{1996};\frac{1996}{1997}\)

Ta thấy:

\(\frac{1995}{1996}=1-\frac{1}{1996}\);\(\frac{1996}{1997}=1-\frac{1}{1997}\).Vì \(\frac{1}{1996}>\frac{1}{1997}\)nên:\(\frac{1995}{1996}>\frac{1996}{1997}\).

b)\(\frac{2121}{3737}=\frac{21\times101}{37\times101}=\frac{21}{37};\frac{212121}{373737}=\frac{21\times10101}{37\times10101}=\frac{21}{37}.\)

Vậy ta có:\(\frac{2121}{3737}=\frac{212121}{373737}.\)