Đáp án + Giải thích các bước giải:
b/`8/24`.`7/7`=`1/3`.`1/1`=`1/3`
`-9/21`.`14/-45`=`1/3`.`2/5`=`2/15`
`-12/-42`.`14/-6`=`2/6`.`-2/1`=`-4/6`=`-2/3`
c/`-32/9`.`-6/40`=`-4/3`.`-2/5`=`8/15
`-15/-24`.`-56/7.10`=`-3/3`.`7/7.2=`21/42`=`1/2`
`-26/15`.`-11/22`.`25/39`=`-26/3`.`-1/2`.`5/39`=`130/234`=`5/9`