51. Найдите разность: 1) 7 8/9 − 2 2/3; 2) 4 17/18 − 2 7/12; 3) 15 8/21 − 6 5/14; 4) 6 19/48 − 5 11/32.

1. \(7\frac{8}{9}-2\frac{2}{3}=5+\frac{8}{9}-\frac{6}{9}=5\frac{2}{9}\).
2. \(4\frac{17}{18}-2\frac{7}{12}=2+\frac{34}{36}-\frac{21}{36}=2\frac{13}{36}\).
3. \(15\frac{8}{21}-6\frac{5}{14}=9+\frac{16}{42}-\frac{15}{42}=9\frac{1}{42}\).
4. \(6\frac{19}{48}-5\frac{11}{32}=1+\frac{38}{96}-\frac{33}{96}=1\frac{5}{96}\).

Ответ: 1) \(5\frac{2}{9}\); 2) \(2\frac{13}{36}\); 3) \(9\frac{1}{42}\); 4) \(1\frac{5}{96}\).