22) \(\frac{5,4}{12-\frac{3}{19}}\)

Преобразуем числа: \(5.4=\frac{27}{5}\), а \(12-\frac{3}{19}=\frac{225}{19}\).

\(\frac{27}{5}:\frac{225}{19}=\frac{27}{5}\cdot\frac{19}{225}=\frac{57}{25}=2.28\).

Ответ: 2,28