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