Задание № 10: 1) 3/4 − 1/4; 2) 6/7 − 3/7; 3) 11/14 − 5/14; 4) 8/15 − 4/15; 5) 12/17 − 3/17; 6) 9/16 − 5/16; 7) 7/9 − 2/9; 8) 10/21 − 3/21.

1. Знаменатели одинаковые, вычитаем числители: \(\frac{3}{4}-\frac{1}{4}=\frac{3-1}{4}=\frac{2}{4}=\frac{1}{2}\).
2. \(\frac{6}{7}-\frac{3}{7}=\frac{6-3}{7}=\frac{3}{7}\).
3. \(\frac{11}{14}-\frac{5}{14}=\frac{11-5}{14}=\frac{6}{14}=\frac{3}{7}\).
4. \(\frac{8}{15}-\frac{4}{15}=\frac{8-4}{15}=\frac{4}{15}\).
5. \(\frac{12}{17}-\frac{3}{17}=\frac{12-3}{17}=\frac{9}{17}\).
6. \(\frac{9}{16}-\frac{5}{16}=\frac{9-5}{16}=\frac{4}{16}=\frac{1}{4}\).
7. \(\frac{7}{9}-\frac{2}{9}=\frac{7-2}{9}=\frac{5}{9}\).
8. \(\frac{10}{21}-\frac{3}{21}=\frac{10-3}{21}=\frac{7}{21}=\frac{1}{3}\).

Ответ: 1) \(\frac{1}{2}\); 2) \(\frac{3}{7}\); 3) \(\frac{3}{7}\); 4) \(\frac{4}{15}\); 5) \(\frac{9}{17}\); 6) \(\frac{1}{4}\); 7) \(\frac{5}{9}\); 8) \(\frac{1}{3}\).