51. Найдите разность: 1) 8 3/7 − 4 2/5; 2) 6 11/15 − 2 7/10; 3) 16 17/18 − 2 11/12; 4) 18 13/48 − 5 3/64.

1. \(8\frac{3}{7}-4\frac{2}{5}=4+\frac{15}{35}-\frac{14}{35}=4\frac{1}{35}\).
2. \(6\frac{11}{15}-2\frac{7}{10}=4+\frac{22}{30}-\frac{21}{30}=4\frac{1}{30}\).
3. \(16\frac{17}{18}-2\frac{11}{12}=14+\frac{34}{36}-\frac{33}{36}=14\frac{1}{36}\).
4. \(18\frac{13}{48}-5\frac{3}{64}=13+\frac{52}{192}-\frac{9}{192}=13\frac{43}{192}\).

Ответ: 1) 4 1/35; 2) 4 1/30; 3) 14 1/36; 4) 13 43/192.