15-6=
12-10=
20+2=
4+16=
7+13=
15-12=
18-10=
12-9=
11+9=
16-12=
12+10=
20-10=
15-7=
10+15=
15-15=
5+20=
9+11=
20-3=
14+5=
10-6=
18+2=
20-2=
15+4=
20-5=
5+13=
12-5=
20-6=
15-3=
17-12=
20+30=
42-2=
15-10=
15+3=
18-8=
5+15=
20-9=
90+5=
10-7=
90-60=
20-9=
12+7=
13+7=
15+5=
12+3=
20-5=
13-12=
4+12=
14-6=
5+15=
10-2=
20+70=
14+11=
60+8=
12+7=
19-16=
40+30=
17+3=
20-12=
65+5=
20-4=