Tính: 7/5 - 3/7

\(\frac{7}{5} - \frac{3}{7} = \frac{{49}}{{35}} - \frac{{15}}{{35}} = \frac{{34}}{{35}}\)

\(\frac{5}{4} - \frac{1}{6} = \frac{{30}}{{24}} - \frac{4}{{24}} = \frac{{26}}{{24}} = \frac{{13}}{{12}}\)

\(\frac{7}{8} - \frac{1}{4} = \frac{7}{8} - \frac{2}{8} = \frac{5}{8}\)

\(\frac{{12}}{{14}} - \frac{3}{7} = \frac{6}{7} - \frac{3}{7} = \frac{3}{7}\)