Ответ:
- \(\frac{2}{3}a\cdot\frac{7}{12}b=\frac{14}{36}ab=\frac{7}{18}ab\).
- \(\frac{8}{9}x\cdot1\frac{4}{5}y=\frac{8}{9}x\cdot\frac{9}{5}y=\frac{8}{5}xy\).
- \(5m\cdot2\frac{6}{11}n\cdot2\frac{5}{14}k=5m\cdot\frac{28}{11}n\cdot\frac{33}{14}k=30mnk\).
- \(2\frac{5}{8}x\cdot2y\cdot2\frac{2}{7}z=\frac{21}{8}x\cdot2y\cdot\frac{16}{7}z=12xyz\).
- \(\frac{7}{8}p\cdot\frac{4}{9}k=\frac{28}{72}pk=\frac{7}{18}pk\).
- \(1\frac{5}{7}x\cdot\frac{5}{12}y=\frac{12}{7}x\cdot\frac{5}{12}y=\frac{5}{7}xy\).
Ответ: а) \(\frac{7}{18}ab\); б) \(\frac{8}{5}xy\); в) \(30mnk\); г) \(12xyz\); д) \(\frac{7}{18}pk\); е) \(\frac{5}{7}xy\).
