4. Выполните деление: а) 6/11 : 12/55; б) 21 : 35; в) 8/9 : 4; г) 6 : 1/3; д) 3/4 : 1 11/12; е) 2 4/15 : 1 7/10; ж) 12 3/5 : 3.

1. \(\dfrac{6}{11}:\dfrac{12}{55}=\dfrac{6}{11}\cdot\dfrac{55}{12}=\dfrac{5}{2}=2\dfrac{1}{2}\).
2. \(21:35=\dfrac{21}{35}=\dfrac{3}{5}\).
3. \(\dfrac{8}{9}:4=\dfrac{8}{9}\cdot\dfrac{1}{4}=\dfrac{2}{9}\).
4. \(6:\dfrac{1}{3}=6\cdot3=18\).
5. \(\dfrac{3}{4}:1\dfrac{11}{12}=\dfrac{3}{4}:\dfrac{23}{12}=\dfrac{3}{4}\cdot\dfrac{12}{23}=\dfrac{9}{23}\).
6. \(2\dfrac{4}{15}:1\dfrac{7}{10}=\dfrac{34}{15}:\dfrac{17}{10}=\dfrac{34}{15}\cdot\dfrac{10}{17}=\dfrac{4}{3}=1\dfrac{1}{3}\).
7. \(12\dfrac{3}{5}:3=\dfrac{63}{5}:3=\dfrac{21}{5}=4\dfrac{1}{5}\).

Ответ: а) \(2\dfrac{1}{2}\); б) \(\dfrac{3}{5}\); в) \(\dfrac{2}{9}\); г) \(18\); д) \(\dfrac{9}{23}\); е) \(1\dfrac{1}{3}\); ж) \(4\dfrac{1}{5}\).