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