Задание 5. Сократите дроби и вычислите: 1) 12/15 + 8/10; 2) 15/21 − 6/14; 3) 24/36 + 18/24; 4) 45/60 − 12/18.

1. \(\frac{12}{15}+\frac{8}{10}=\frac{4}{5}+\frac{4}{5}=\frac{8}{5}=1\frac{3}{5}\).
2. \(\frac{15}{21}-\frac{6}{14}=\frac{5}{7}-\frac{3}{7}=\frac{2}{7}\).
3. \(\frac{24}{36}+\frac{18}{24}=\frac{2}{3}+\frac{3}{4}=\frac{8}{12}+\frac{9}{12}=\frac{17}{12}=1\frac{5}{12}\).
4. \(\frac{45}{60}-\frac{12}{18}=\frac{3}{4}-\frac{2}{3}=\frac{9}{12}-\frac{8}{12}=\frac{1}{12}\).

Ответ: 1) \(1\frac{3}{5}\); 2) \(\frac{2}{7}\); 3) \(1\frac{5}{12}\); 4) \(\frac{1}{12}\).