Câu 2
b ) `5/12` : `7/4` - `25/18` : `35/6`
= `5/12` x `4/7` - `25/8` x `6/35`
= `20/84` - `150/280`
= `5/21` - `5/21`
= `0`
Câu 3
`2/5` + `1/2` - `7/10`
= `4/10` + `5/10` - `7/10`
= `9/10` - `7/10`
= `2/10` = `1/5`
`4/7` : `8/11`
= `4/7` x `11/8`
= `44/56` = `11/14`
Mik xin hay nhất ạ !