В) \((0,7 - \frac{7}{20}) \cdot 2\frac{2}{9} - 0,4 : 1,8\);

\(0,7 - \frac{7}{20} = \frac{7}{10} - \frac{7}{20} = \frac{14}{20} - \frac{7}{20} = \frac{7}{20}\)

\(\frac{7}{20} \cdot 2\frac{2}{9} = \frac{7}{20} \cdot \frac{20}{9} = \frac{7}{9}\)

\(0,4 : 1,8 = \frac{4}{10} : \frac{18}{10} = \frac{4}{10} \cdot \frac{10}{18} = \frac{4}{18} = \frac{2}{9}\)

\(\frac{7}{9} - \frac{2}{9} = \frac{5}{9}\)

Ответ: \(\frac{5}{9}\)