13/14. 17/18 2021/2020. 1 19951994. 1994/1993 2121/3636. 7/12

Đáp án:

`a)`

`=>13/14=1-1/14`

`=>17/18=1-1/18`

`=>1/14>1/18`

`=>1-1/14<1-1/18`

`=>13/14<17/18`

Vậy `13/14<17/18`.

`b)`

`=>2021/2020=1+1/2020`

`=>1+1/2020>1`

`=>2021/2020>1`

Vậy `2021/2020>1`.

`c)`

`=>1995/1994=1+1/1994`

`=>1994/1993=1+1/1993`

`=>1/1994<1/1993`

`=>1+1/1994<1+1/1993`

`=>1995/1994<1994/1993`

Vậy `1995/1994<1994/1993`.

`d)` 

`=>2121/3636=21/36=(21:3)/(36:3)=7/12`

`=>2121/3636=7/12`

Vậy `2121/3636=7/12`.