ПОМОГИТЕ!!!! Сократите дробь-1068/1869,486/729,1048/1834,516/1290,18/30,20/50,54/63 и...

Решите задачу:

$\frac{1068}{1869}= \frac{2*2*3*89}{3*7*89}=\frac{2*2}{7}=\frac{4}{7}.$
$\frac{486}{729}= \frac{2*3*3*3*3*3}{3*3*3*3*3*3}=\frac{2}{3}.$
$\frac{1048}{1834}= \frac{2*2*2*131}{2*7*131}=\frac{2*2}{7}=\frac{4}{7}.$
$\frac{516}{1290}= \frac{2*2*3*43}{2*3*5*43}=\frac{2}{5}.$
$\frac{18}{30}= \frac{2*3*3}{2*3*5}=\frac{3}{5}.$
$\frac{20}{50}=\frac{2}{5}.$
$\frac{54}{63}= \frac{6*9}{7*9}=\frac{6}{7}.$
$\frac{28}{70}= \frac{2*14}{5*14}=\frac{2}{5}.$