a)Ta có:\(-\frac{2}{7}=\frac{-2.11}{7.11}=-\frac{22}{77}\)
\(-\frac{3}{11}=\frac{-3.7}{11.7}=-\frac{21}{77}\)
Vì \(-\frac{22}{77}< -\frac{21}{77}\)
Vậy \(-\frac{2}{7}< -\frac{3}{11}\)
b)Ta có:\(-\frac{28}{25}=\frac{-28.12}{25.12}=-\frac{336}{300}\)
Vì \(-\frac{336}{300}< -\frac{213}{300}\)
Vậy \(-\frac{28}{25}< -\frac{213}{300}\)
c)Ta có:\(-\frac{3}{4}=-0,75\)
Vì -0,75=-0,75
Vậy \(-\frac{3}{4}=-0,75\)