4/5-(2/15+1/9)=4/5-2/15-1/9=2/3-1/9 =5=9
答案是九分之五
5/4-(2/15+1/9)=5/4-(6/45+5/45)=5/4-11/45=225/180-44/180=181/180
答案是: 9分之5
9分之5