Ta có: \(\frac56=1-\frac16;\frac78=1-\frac18;\frac{9}{10}=1-\frac{1}{10}\)
Ta có: 6<8<10
=>\(\frac16>\frac18>\frac{1}{10}\)
=>\(-\frac16<-\frac18<-\frac{1}{10}\)
=>\(-\frac16+1<-\frac18+1<-\frac{1}{10}+1\)
=>\(\frac56<\frac78<\frac{9}{10}\) <1
mà \(1=\frac88;1=\frac55<\frac65\)
nên \(\frac56<\frac78<\frac{9}{10}<\frac88<\frac65\)