5/9-3/8+7/16=89/144
5/18+2/9-1/3-1/4=-1/12
11/12-1/4-1/9=5/9有没有过程5/9-3/8+7/16=80/144-54/144+63/144=89/1445/18+2/9-1/3-1/4=10/36+8/36-12/36-9/36=-3/36=-1/1211/12-1/4-1/9=33/36-9/36-4/36=20/36=5/9