(二十五分之三十八减二十三分之九)除以(二十五分之九减二十三分之二十)
=(38×23-9×25)/(25*23)÷(9×23-21×25)/(25*23)
=(28×23-9×25)/(9×23-21×25)
=(644-225)/(207-525)
=419/(-318)
=-419/318
=-318分之419
(38/25-9/23)/(9/25-21/23)
=(649/575)/(-318/575)
=-649/318
(38/25-9/23)/(9/25)-12/23
=(38/25-9/23)*(25/9)-12/23
=(38/9-25/23)-12/23
=4又2/9-13/23