10-2= 9+7= 6+8= 5+9=
12-4= 7+9= 20-2= 11-2=
20-3= 9+8= 18-9= 20-9=
12-7= 10-8= 17-8= 9+2=
8+3= 6+8= 9+2= 6+9=
10-2= 9+7= 6+8= 5+9=
12-4= 7+9= 20-2= 11-2=
20-3= 9+8= 18-9= 20-9=
12-7= 10-8= 17-8= 9+2=
8+3= 6+8= 9+2= 6+9=