7+5= 14-4= 11+9 = 11-6= （）-8=8
17-10-4= 6+6+7= 16-10+9= 4+6-8=
12-10+2= 7+9-8= 18-12-3= 19-6= 15+2= 14-3= 12+7= 6+9= 7=12= 16-8= 17+1=
