4 12-8+9 10+3-8 17-8+6 14-7+6 10+4-9 18-9+8 48-40-8 56-50+0 0+88-80

1. $12-8+9$ = 13<br />2. $10+3-8$ = 5<br />3. $17-8+6$ = 15<br />4. $14-7+6$ = 13<br />5. $10+4-9$ = 5<br />6. $18-9+8$ = 17<br />7. $48-40-8$ = 0<br />8. $56-50+0$ = 6<br />9. $0+88-80$ = 8