\(\boxed{\mathbf{2.}\mathbf{53}\mathbf{.\ ОК\ ГДЗ - домашка\ на\ }5}\)
\[\textbf{а)}\ \frac{4}{9} + \frac{7}{9} - \frac{1}{9} = \frac{4 + 7 - 1}{9} = \frac{10}{9} =\]
\[= 1\frac{1}{9}\]
\[\textbf{б)}\ \frac{6}{7} - \left( \frac{5}{7} - \frac{1}{7} \right) = \frac{6}{7} - \frac{5}{7} + \frac{1}{7} =\]
\[= \frac{6 - 5 + 1}{7} = \frac{2}{7}\]
\[\textbf{в)}\ 5\frac{6}{39} + 4\frac{7}{39} = 9\frac{6 + 7}{39} = 9\frac{13}{39}\]
\[\textbf{г)}\ 7\frac{13}{15} - 3\frac{8}{15} = 4\frac{13 - 8}{15} =\]
\[= 4\frac{5}{15} = 4\frac{1}{3}\]
\[\textbf{д)}\ \frac{7}{8} \cdot \frac{4}{35} \cdot \frac{10}{9} = \frac{7 \cdot 4 \cdot 5 \cdot 2}{4 \cdot 2 \cdot 5 \cdot 7 \cdot 9} =\]
\[= \frac{1}{9}\]
\[\textbf{е)}\ \left( \frac{1}{2}\ :\frac{3}{4} - \frac{4}{9} \right) \cdot \frac{5}{3} =\]
\[= \left( \frac{1}{2} \cdot \frac{4}{3} - \frac{4}{9} \right) \cdot \frac{5}{3} =\]
\[= \left( \frac{2^{\backslash 3}}{3} - \frac{4}{9} \right) \cdot \frac{5}{3} = \left( \frac{6}{9} - \frac{4}{9} \right) \cdot \frac{5}{3} =\]
\[= \frac{2}{9} \cdot \frac{5}{3} = \frac{10}{27}\]