10) 1 1/12 : (1 13/18 - 5/9)

10) \(1\frac{1}{12} : (1\frac{13}{18} - \frac{5}{9}) = \frac{13}{12} : (\frac{31}{18} - \frac{5}{9}) = \frac{13}{12} : (\frac{31}{18} - \frac{10}{18}) = \frac{13}{12} : \frac{21}{18} = \frac{13}{12} \cdot \frac{18}{21} = \frac{13}{2} \cdot \frac{3}{21} = \frac{13}{2} \cdot \frac{1}{7} = \frac{13}{14}\)
Ответ: 13/14