Bài 1:
a) \(\dfrac{1}{6}=\dfrac{1\times5}{6\times5}=\dfrac{5}{30}\) và \(\dfrac{7}{30}\)
b) \(\dfrac{10}{7}=\dfrac{10\times6}{7\times6}=\dfrac{60}{42}\) và \(\dfrac{5}{6}=\dfrac{5\times7}{6\times7}=\dfrac{35}{42}\)
Bài 2:
a) \(\dfrac{11}{12}=\dfrac{11\times5}{12\times5}=\dfrac{55}{60}\)
\(\dfrac{9}{10}=\dfrac{9\times6}{10\times6}=\dfrac{54}{60}\)
Do 55>54 nên \(\dfrac{11}{12}>\dfrac{9}{10}\)
b) \(\dfrac{12}{19}=\dfrac{12\times3}{19\times3}=\dfrac{36}{57}\)
\(\dfrac{22}{33}=\dfrac{2}{3}=\dfrac{2\times19}{3\times19}=\dfrac{38}{57}\)
Do 36<38 nên \(\dfrac{12}{19}< \dfrac{22}{33}\)
c) \(\dfrac{12}{13}=\dfrac{12\times101}{13\times101}=\dfrac{1212}{1313}\)