7) 1 1/4 − 5/12; 8) 14 2/3 − 11 7/9; 9) 3/5 − 5/13; 10) 12 1/45 − 8 2/27; 11) 9 1/4 − 2 7/25; 12) 7 3/22 − 5/77; 13) 7/12 − 1/18; 14) 5 1/6 − 1/25; 15) 9 17/60 − 1 5/42; 16) 5/8 − 4/7; 17) 16 5/16 − 8 1/4

1. \(1\frac{1}{4}-\frac{5}{12}=\frac{15}{12}-\frac{5}{12}=\frac{10}{12}=\frac{5}{6}\).
2. \(14\frac{2}{3}-11\frac{7}{9}=14\frac{6}{9}-11\frac{7}{9}=13\frac{15}{9}-11\frac{7}{9}=2\frac{8}{9}\).
3. \(\frac{3}{5}-\frac{5}{13}=\frac{39}{65}-\frac{25}{65}=\frac{14}{65}\).
4. Общий знаменатель дробных частей — 135: \(12\frac{3}{135}-8\frac{10}{135}=11\frac{138}{135}-8\frac{10}{135}=3\frac{128}{135}\).
5. Общий знаменатель — 100: \(9\frac{25}{100}-2\frac{28}{100}=8\frac{125}{100}-2\frac{28}{100}=6\frac{97}{100}\).
6. \(7\frac{3}{22}-\frac{5}{77}=7\frac{21}{154}-\frac{10}{154}=7\frac{11}{154}=7\frac{1}{14}\).
7. \(\frac{7}{12}-\frac{1}{18}=\frac{21}{36}-\frac{2}{36}=\frac{19}{36}\).
8. \(5\frac{1}{6}-\frac{1}{25}=5\frac{25}{150}-\frac{6}{150}=5\frac{19}{150}\).
9. \(9\frac{17}{60}-1\frac{5}{42}=9\frac{119}{420}-1\frac{50}{420}=8\frac{489}{420}-1\frac{50}{420}=7\frac{439}{420}=8\frac{19}{420}\).
10. \(\frac{5}{8}-\frac{4}{7}=\frac{35}{56}-\frac{32}{56}=\frac{3}{56}\).
11. \(16\frac{5}{16}-8\frac{1}{4}=16\frac{5}{16}-8\frac{4}{16}=8\frac{1}{16}\).

Ответ: 7) 5/6; 8) 2 8/9; 9) 14/65; 10) 3 128/135; 11) 6 97/100; 12) 7 1/14; 13) 19/36; 14) 5 19/150; 15) 8 19/420; 16) 3/56; 17) 8 1/16.