15-6=15-7=15-8=15-9=
18-10= 17-11= 17-8= 17-13= 17-9= 3+17= 2+18= 3+13= 13+4= 13-5= 19-13= 18-12= 18-9= 18-10= 18-14= 3+16= 3+17= 4+14= 14-5= 14+6= 13-5= 13-6= 13-7= 13-8=13-9=
4+7=
4+8=
4+9=
4+10=
4+15=
13-10=
12-9=
12-3=
12-4=
12-5=
4+12=
4+13=
4+14=
4+15=
4+16=
11+9=
11-2=
11-3=
11-4=
11-5=
11+7=
6+6=
8+8=
9+11=
7+9=
14-8=
15-6=
16-9=
17-8=
18-9=
9+9=
7+5=
8+6=
5+9=
13-8=
15-5=
15-6=
15-7=
15-8=
15-9=
13-11=
12-7=
19-13=
12-8=
20-14=
14-12=
14-9=