7+5= 8+9= 6+8= 14-8= 16-9=
11-7= 15-7= 17-9= 14-6= 5+8=
12-6= 12-3= 5+6= 13-4= 9+4=
13-5= 2+9= 16-7= 3+7= 12-5=
16-9= 17-8= 15-7= 11-4= 3+9=
14-6= 5+9= 12-5= 4+9= 12-3=
15-8
A.17-10
14-6
B.11-2
18-9
C.16-8
(从12-6开始,按 方向计算)