\[\boxed{\mathbf{2.2}\mathbf{82}}\]
\[\textbf{а)}\ \frac{1}{8} = \frac{1}{2} \cdot \frac{1}{4}\]
\[\textbf{б)}\ \frac{5}{9} = \frac{1}{3} \cdot \frac{5}{3}\]
\[\textbf{в)}\ \frac{15}{14} = \frac{5}{7} \cdot \frac{3}{2}\]
\[\textbf{г)}\ 1\frac{7}{18} = \frac{25}{18} = \frac{5}{3} \cdot \frac{5}{6}\]