Вариант 4. 1. Выполните умножение: 1) 8/20 · 5/60; 2) 5/6 · 7/9; 3) 17/88 · 24/37; 4) 27/56 · 35/81.

1. \(\frac{8}{20}\cdot\frac{5}{60}=\frac{2}{5}\cdot\frac{1}{12}=\frac{1}{30}\).
2. \(\frac{5}{6}\cdot\frac{7}{9}=\frac{35}{54}\).
3. \(\frac{17}{88}\cdot\frac{24}{37}=\frac{17}{11\cdot37}\cdot3=\frac{51}{407}\).
4. \(\frac{27}{56}\cdot\frac{35}{81}=\frac{1}{3}\cdot\frac{5}{8}=\frac{5}{24}\).

Ответ: 1) \(\frac{1}{30}\); 2) \(\frac{35}{54}\); 3) \(\frac{51}{407}\); 4) \(\frac{5}{24}\).