Ответ:
а) \[\frac{4}{9}:\frac{63}{64}:\frac{2}{7}=\frac{4}{9}\cdot\frac{64}{63}\cdot\frac{7}{2}=\frac{128}{81}\]
б) \[\left(\frac12\right)^2:\frac56:\frac7{15}=\frac14\cdot\frac65\cdot\frac{15}{7}=\frac9{14}\]
в) \[\left(1-\frac13\right):\left(\frac13-\frac14\right)=\frac23:\frac1{12}=8\]
Ответ: а) \(\frac{128}{81}\); б) \(\frac9{14}\); в) 8.
