A, \(\dfrac{7}{9}\) = \(\dfrac{7\cdot5}{9\cdot5}\) = \(\dfrac{35}{45}\) \(\dfrac{3}{5}\) = \(\dfrac{3\cdot9}{5\cdot9}\) = \(\dfrac{27}{45}\)
Vậy \(\dfrac{7}{9}\) > \(\dfrac{3}{5}\)
B, \(\dfrac{3}{4}\) = \(\dfrac{3\cdot6}{4\cdot6}\) = \(\dfrac{18}{24}\) \(\dfrac{5}{6}\) = \(\dfrac{5\cdot4}{6\cdot4}\) = \(\dfrac{20}{24}\)
Vậy \(\dfrac{3}{4}\) < \(\dfrac{5}{6}\)
C, \(\dfrac{1}{4}\) = \(\dfrac{1\cdot3}{4\cdot3}\) = \(\dfrac{3}{12}\) \(\dfrac{2}{3}\) = \(\dfrac{2\cdot4}{3\cdot4}\) = \(\dfrac{8}{12}\)
Vậy \(\dfrac{1}{4}\) < \(\dfrac{2}{3}\)
D, \(\dfrac{8}{9}\) = \(\dfrac{8\cdot2}{9\cdot2}\) = \(\dfrac{16}{18}\) \(\dfrac{1}{2}\) = \(\dfrac{1\cdot9}{2\cdot9}\) = \(\dfrac{9}{18}\)
Vậy \(\dfrac{8}{9}\) > \(\dfrac{1}{2}\)
\(\cdot\) là dấu nhân
