个
12-411-4 14-813-7 15-5+316-7+3
17-818-8 19-917-9 11-5+613-4+5
问题:
解答:
13-7=(4)
10-5= 6-4= 7-3= 8-2=
9-0= 9-4= 8-5= 7-6=
10-5= 6-0= 8-2= 7-3=
5-1= 6-0= 4-2= 6-3=
7-6= 5-4= 2-0= 9-6=