Выполните действие: 1 4/15 − 17/20; 7 4/15 − 7/9; в) 2 5/12 − 7/8; г) 11 1/2 − 3 11/18; д) 9 2/11 − 7 5/9; е) 2 6/25 − 1 7/10; ж) 3 1/2 − 2 3/4; з) 12 5/12 − 9 13/18.

Приведём дроби к общему знаменателю: \(1\frac{4}{15}-\frac{17}{20}=1+\frac{16}{60}-\frac{51}{60}=\frac{25}{60}=\frac{5}{12}\).

\(7\frac{4}{15}-\frac{7}{9}=7+\frac{12}{45}-\frac{35}{45}=6+\frac{22}{45}=6\frac{22}{45}\).

\(2\frac{5}{12}-\frac{7}{8}=2+\frac{10}{24}-\frac{21}{24}=1+\frac{13}{24}=1\frac{13}{24}\).

\(11\frac{1}{2}-3\frac{11}{18}=11\frac{9}{18}-3\frac{11}{18}=7\frac{16}{18}=7\frac{8}{9}\).

\(9\frac{2}{11}-7\frac{5}{9}=9\frac{18}{99}-7\frac{55}{99}=1\frac{62}{99}\).

\(2\frac{6}{25}-1\frac{7}{10}=2\frac{12}{50}-1\frac{35}{50}=\frac{27}{50}\).

\(3\frac{1}{2}-2\frac{3}{4}=3\frac{2}{4}-2\frac{3}{4}=\frac{3}{4}\).

\(12\frac{5}{12}-9\frac{13}{18}=12\frac{15}{36}-9\frac{26}{36}=2\frac{25}{36}\).