138. Выполните деление: a) 14/39:21/52; 6) 4 1/11:2 19/22; в) 18:9/14.

a) \(\frac{14}{39}:\frac{21}{52} = \frac{14}{39} \cdot \frac{52}{21} = \frac{2}{3} \cdot \frac{4}{3} = \frac{8}{9}\)

б) \(4 \frac{1}{11}:2 \frac{19}{22} = \frac{45}{11}:\frac{63}{22} = \frac{45}{11} \cdot \frac{22}{63} = \frac{5}{1} \cdot \frac{2}{7} = \frac{10}{7} = 1 \frac{3}{7}\)

в) \(18:\frac{9}{14} = 18 \cdot \frac{14}{9} = 2 \cdot 14 = 28\)

Ответ: а) \(\frac{8}{9}\); б) 1 \(\frac{3}{7}\); в) 28