9) \( 3\frac{1}{5} - \left( -4\frac{1}{7} \right) \)

\( 3\frac{1}{5} - \left( -4\frac{1}{7} \right) = 3\frac{1}{5} + 4\frac{1}{7} = \frac{16}{5} + \frac{29}{7} = \frac{112}{35} + \frac{145}{35} = \frac{257}{35} = 7\frac{12}{35} \)