Вариант 1. 3. Выполните действия: а) \(\left(11-9\frac{18}{29}\right)\cdot\frac{29}{80}\); б) \(1\frac{41}{64}:\left(7\frac{3}{16}-5\right)\); в) \(\frac{42}{31}\cdot\frac{93}{25}:\frac{14}{75}\); г) \(\frac{4}{\frac1{19}-\frac1{21}}\).

1. \[\left(11-9\frac{18}{29}\right)\cdot\frac{29}{80}=\frac{32}{29}\cdot\frac{29}{80}=\frac25.\]
2. \[1\frac{41}{64}:\left(7\frac3{16}-5\right)=\frac{105}{64}:\frac{35}{16}=\frac{105}{64}\cdot\frac{16}{35}=\frac34.\]
3. \[\frac{42}{31}\cdot\frac{93}{25}:\frac{14}{75}=\frac{42}{31}\cdot\frac{93}{25}\cdot\frac{75}{14}=\frac{837}{31}.\]
4. \[\frac4{\frac1{19}-\frac1{21}}=\frac4{\frac{21-19}{399}}=\frac4{\frac2{399}}=798.\]

Ответ: а) \(\frac25\); б) \(\frac34\); в) \(\frac{837}{31}\); г) \(798\).