Й) \(3\frac{5}{6} - 1\frac{4}{9}\)

\(3\frac{5}{6} - 1\frac{4}{9} = \frac{3 \times 6 + 5}{6} - \frac{1 \times 9 + 4}{9} = \frac{23}{6} - \frac{13}{9}\)

Приводим к общему знаменателю 18:

\(\frac{23}{6} = \frac{23 \times 3}{6 \times 3} = \frac{69}{18}\)

\(\frac{13}{9} = \frac{13 \times 2}{9 \times 2} = \frac{26}{18}\)

\(\frac{69}{18} - \frac{26}{18} = \frac{69-26}{18} = \frac{43}{18} = 2\frac{7}{18}\)

Ответ: \(2\frac{7}{18}\).