13+7-17=  5-5+7=

7+13-15=  2+11+3=

17-2-3=  14-10+16=

18-12+11=  6+8-9=

15-12+16=  13-4+11=

2+16-6=  5+4+10=

16-7+9=  10+5-2=

15+4-7=  15-2+4=

18-9-5=  20-9+5=

5-1-4=  18-7-5=

15-12+16=  13-4+11=

2+16-6=  5+4+10=

16-7+9=  10+5-2=

15+4-7=  15-2+4=

18-9-5=  20-9+5=

5-1-4=  18-7-5=

12+2-12=  14-14+19=

2+2+15=  1+12-7=

17-17+17=  19-7+5=

5+3+7=  17-6+6=