a) \(\dfrac{13}{15}< \dfrac{14}{15}\) ( vì 13 < 14 )
b) Ta có:
\(\dfrac{2}{3}=\dfrac{2\times3}{3\times3}=\dfrac{6}{9}\)
Vì 6 = 6 nên \(\dfrac{6}{9}=\dfrac{6}{9}\)
Vậy \(\dfrac{2}{3}=\dfrac{6}{9}\)
c) Ta có:
\(\dfrac{4}{7}=\dfrac{4\times6}{7\times6}=\dfrac{24}{42}\)
\(\dfrac{5}{6}=\dfrac{5\times7}{6\times7}=\dfrac{35}{42}\)
Vì 24 < 35 nên \(\dfrac{24}{42}< \dfrac{35}{42}\)
Vậy \(\dfrac{4}{7}< \dfrac{5}{6}\)
d) Vì 9 < 13 nên \(\dfrac{4}{9}>\dfrac{4}{13}\)
Vậy \(\dfrac{4}{9}>\dfrac{4}{13}\)