第94页

信息发布者:
​$\frac {2}{5}+\frac {2}{5}= \frac {4}{5}$​
​$\frac {6}{7}-\frac {2}{7}= \frac {4}{7}$​
$\frac{7}{9}$
$1$
$\frac{3}{4}$
$4\frac{1}{4}$
$\frac{2}{3}$
$\frac{3}{5}$
$\frac{5}{9}$
$\frac{19}{30}$