2. Упростите выражения: 1) 6 \(\cdot\) (-3a) \(\cdot\) (-45b); 2) -32x \(\cdot\) 4 \(\cdot\) (-25y); 3) \(\frac{5}{6}m \cdot \frac{3}{4}n \cdot \frac{2}{5}\); 4) \(\frac{16}{25}x \cdot \frac{5}{8}y \cdot \frac{3}{4}\); 5) -2n \(\cdot\) 3r \(\cdot\) (-5k); 6) 16 \(\frac{2}{3}\)a \(\cdot\) \(\frac{3}{25}\)b \(\cdot\) \(\frac{3}{4}\)

2. Упрощение выражений:

1. \( 6 \cdot (-3a) \cdot (-45b) = 6 \cdot (-3) \cdot (-45) \cdot a \cdot b = 18 \cdot 45 \cdot ab = \textbf{810ab} \)
2. \( -32x \cdot 4 \cdot (-25y) = -32 \cdot 4 \cdot (-25) \cdot x \cdot y = -128 \cdot (-25) \cdot xy = \textbf{3200xy} \)
3. \( \frac{5}{6}m \cdot \frac{3}{4}n \cdot \frac{2}{5} = \frac{5 \cdot 3 \cdot 2}{6 \cdot 4 \cdot 5} m n = \frac{30}{120} mn = \textbf{\frac{1}{4}mn} \)
4. \( \frac{16}{25}x \cdot \frac{5}{8}y \cdot \frac{3}{4} = \frac{16 \cdot 5 \cdot 3}{25 \cdot 8 \cdot 4} xy = \frac{240}{800} xy = \textbf{\frac{3}{10}xy} \)
5. \( -2n \cdot 3r \cdot (-5k) = (-2) \cdot 3 \cdot (-5) \cdot n \cdot r \cdot k = 30 n r k = \textbf{30n r k} \)
6. \( 16 \frac{2}{3}a \cdot \frac{3}{25}b \cdot \frac{3}{4} = \frac{16 \cdot 3 + 2}{3}a \cdot \frac{3}{25}b \cdot \frac{3}{4} = \frac{50}{3}a \cdot \frac{3}{25}b \cdot \frac{3}{4} = \frac{50 \cdot 3 \cdot 3}{3 \cdot 25 \cdot 4} ab = \frac{450}{300} ab = \textbf{\frac{3}{2}ab} \)

Ответ: 1) \( 810ab \); 2) \( 3200xy \); 3) \(\frac{1}{4}mn \); 4) \(\frac{3}{10}xy \); 5) \( 30n r k \); 6) \(\frac{3}{2}ab \).