文档介绍：81-7= 36-7= 31-7= 10-3= 34-5=
55-8= 15-9= 12-4= 55-9= 25-6=
20-6= 62-9= 92-7= 74-9= 23-6=
10-5= 92-5= 10-8= 31-5= 12-4=
92-5= 65-8= 50-4= 16-8= 12-6=
75-7= 15-6= 82-5= 93-9= 45-7=
85-9= 92-8= 31-6= 62-5= 45-9=
10-6= 82-5= 95-8= 23-4= 50-3=
43-4= 70-5= 31-7= 51-2= 82-3=
92-5= 25-9= 44-6= 73-8= 90-6=
76-7= 32-9= 10-7= 33-5= 70-2=
12-7= 46-8= 45-6= 41-7= 23-9=
90-7= 10-4= 72-6= 21-5= 23-5=
81-2= 52-4= 73-6= 81-5= 16-8=
70-4= 80-8= 44-6= 60-5= 51-5=
80-9= 72-4= 94-5= 13-8= 64-8=
31-5= 20-2= 13-7= 32-4= 71-6=
53-7= 51-3= 50-5= 72-3= 67-8=
74-9= 50-2= 61-5= 27-9= 32-3=
72-7= 70-5= 32-6= 73-7= 60-3=
61-7= 50-1= 45-6= 63-6= 40-8=
47-8= 27-8= 63-4= 82-3= 44-8=
43-5= 96-9= 71-3= 52-4= 72-9=
51-3= 80-5= 50-2= 93-4= 30-9=
31-4= 85-6= 41-7= 32-3= 30-2=
35-8= 81-4= 60-8= 92-3= 31-4=