45. \(2\frac{2}{3} : 1\frac{31}{31}\)

Решение:

\(2\frac{2}{3} \div 1\frac{31}{31} = \frac{8}{3} \div 2 = \frac{8}{3} \times \frac{1}{2} = \frac{8 \times 1}{3 \times 2} = \frac{8}{6} = \frac{4}{3}\)

Ответ: \(\frac{4}{3}\)