Problem : 7 - 19 = ?

Problem : -5 - 6 = ?

Problem : 8 - 12 = ?

Problem : 7 + (- 4) = ?

Problem : 102 + (- 99) = ?

Problem : 54 - (- 16) = ?

Problem : 17 - (- 12) = ?

Problem : -9 - (- 10) = ?

Problem : 7×(- 8) = ?

Problem : -11×(- 5)/5×(- 9) = ?

Problem : 12/(- 4)×(- 3) = ?