\[\boxed{\mathbf{2.529}}\]
\[1)\ \frac{1}{7} \rightarrow 7\]
\[7 > \frac{1}{7}\ \]
\[7\ :\frac{1}{7} = 7 \cdot 7 = в\ 49\ раз.\]
\[2)\ \frac{3}{4} \rightarrow \frac{4}{3}\]
\[\frac{4}{3} > \frac{3}{4}\ \]
\[\frac{4}{3}\ :\frac{3}{4} = \frac{4}{3} \cdot \frac{4}{3} = в\ \ \frac{16}{9}\ раз.\]
\[3)\ \frac{1}{9} \rightarrow 9\]
\[9 > \frac{1}{9}\ \]
\[9\ :\frac{1}{9} = 9 \cdot 9 = в\ 81\ раз.\]
\[4)\ 0,4 = \frac{4}{10} = \frac{2}{5} \rightarrow \frac{5}{2}\]
\[\frac{5}{2} > \frac{2}{5}\ \]
\[\frac{5}{2}\ :\frac{2}{5} = \frac{5}{2} \cdot \frac{5}{2} = в\ \frac{25}{4}\ раз.\]