Rút gọn phân số 25/40 ; 36/42 ; 12 /20 ; 14/26 ; 6/9 ; 14/21 ; 16/56 ; 18/81 về phân số tối giản:

Rút gọn phân số, ta được:

\[\frac{{25}}{{40}} = \frac{{25:5}}{{40:5}} = \frac{5}{8}\]

\(\frac{{36}}{{42}} = \frac{{36:6}}{{42:6}} = \frac{6}{7}\)

\(\frac{{12}}{{20}} = \frac{{12:4}}{{20:4}} = \frac{3}{5}\)

\(\frac{{14}}{{26}} = \frac{{14:2}}{{26:2}} = \frac{7}{{13}}\)

\(\frac{6}{9} = \frac{{6:3}}{{9:3}} = \frac{2}{3}\)

\(\frac{{14}}{{21}} = \frac{{14:7}}{{21:7}} = \frac{2}{3}\)

\(\frac{{16}}{{56}} = \frac{{16:8}}{{56:8}} = \frac{2}{7}\)

\(\frac{{18}}{{81}} = \frac{{18:9}}{{81:9}} = \frac{2}{9}\)