a/b=(a*n)/(b*n)=(a/n)/(b/n)

700? 25

=700? 425? 4?

=2800? 100

=28

?

()(? )

68? 17? 17=68(? 68? 17? 17=68)?

320? (2? 5? 8)=320? 2? 5? 8=4?

56? (8? 4)=56? 8? 4=28?