2. Вычислите: 1) 4 · 5/21; 2) 24 · 7/12; 3) 16/63 · 9; 4) 36 · 13/48.

1. \(4\cdot\frac{5}{21}=\frac{20}{21}\).
2. \(24\cdot\frac{7}{12}=2\cdot7=14\).
3. \(\frac{16}{63}\cdot9=\frac{16}{7}\).
4. \(36\cdot\frac{13}{48}=\frac{3}{4}\cdot13=\frac{39}{4}=9\frac{3}{4}\).

Ответ: 1) 20/21; 2) 14; 3) 16/7; 4) 9 3/4.