1) 17/18 − 10/18; 2) 5 8/9 − 3; 3) 7 3/8 − 2 1/8; 4) 6 5/9 − 4/9; 5) 1 − 11/14; 6) 5 − 3/19; 7) 18 − 5 19/100; 8) 1 − 10/23; 9) 5/14 − 1/14; 10) 5 − 7/9; 11) 12 3/10 − 9/10; 12) 13 7/17 − 9 13/17.

1. \(\frac{17}{18}-\frac{10}{18}=\frac{7}{18}\).
2. \(5\frac{8}{9}-3=2\frac{8}{9}\).
3. \(7\frac{3}{8}-2\frac{1}{8}=5\frac{2}{8}=5\frac{1}{4}\).
4. \(6\frac{5}{9}-\frac{4}{9}=6\frac{1}{9}\).
5. \(1-\frac{11}{14}=\frac{14}{14}-\frac{11}{14}=\frac{3}{14}\).
6. \(5-\frac{3}{19}=\frac{95}{19}-\frac{3}{19}=\frac{92}{19}=4\frac{16}{19}\).
7. \(18-5\frac{19}{100}=12\frac{81}{100}\).
8. \(1-\frac{10}{23}=\frac{13}{23}\).
9. \(\frac{5}{14}-\frac{1}{14}=\frac{4}{14}=\frac{2}{7}\).
10. \(5-\frac{7}{9}=4\frac{2}{9}\).
11. \(12\frac{3}{10}-\frac{9}{10}=11\frac{13}{10}=11\frac{3}{10}\).
12. \(13\frac{7}{17}-9\frac{13}{17}=12\frac{24}{17}=12\frac{7}{17}\).

Ответ: 1) \(\frac{7}{18}\); 2) \(2\frac{8}{9}\); 3) \(5\frac{1}{4}\); 4) \(6\frac{1}{9}\); 5) \(\frac{3}{14}\); 6) \(4\frac{16}{19}\); 7) \(12\frac{81}{100}\); 8) \(\frac{13}{23}\); 9) \(\frac{2}{7}\); 10) \(4\frac{2}{9}\); 11) \(11\frac{3}{10}\); 12) \(12\frac{7}{17}\).