(5/6-3/4)除(2/3+4/9)

8✘9✘10
+7✘8✘9-6✘7✘8
+5✘6✘7-4✘5✘6
+3✘4✘5-2✘3✘4
=720
+7✘8✘3+5✘6✘3+3✘4✘3
=720+（56+30+12）✘3
=720+98✘3
=720+300-6=1014本回答被网友采纳

(5/6-3/4)÷(2/3+4/9)
=1/12÷10/9
=1/12×9/10
=3/40