Đáp án:
`b)`
`-1/2<0`
`4/9 ; 3/7 >0`
`MSC : 63`
`4/9=(4.7)/(9.7)=28/63 ; 3/7=(3.9)/(7.9)=27/63`
Vì : `27/63<28/63 => 3/7<4/9`
`=> -1/2<3/7<4/9`
`c)`
`-48/78 ; 64/-95`
`-48/78=-8/13 ; 64/-95=-64/95`
`MSC : 1235`
`-8/13=((-8).95)/(13.95)=-760/1235`
`-64/95=((-64).8)/(95.8)=-512/1235`
Vì : `-760/1235< -512/1235`
`=> -8/13<-64/95` hay `-48/78<-64/95`