4) - 60
5 - 15 + 30 - 45 + 20 - 100 + 45 = -10 + 30 - 45 + 20 - 100 + 45 = 20 - 45 + 20 - 100 + 45 = -25 + 20 - 100 + 45 = -5 - 100 + 45 = -105 + 45 = -60
4) - 60
5 - 15 + 30 - 45 + 20 - 100 + 45 = -10 + 30 - 45 + 20 - 100 + 45 = 20 - 45 + 20 - 100 + 45 = -25 + 20 - 100 + 45 = -5 - 100 + 45 = -105 + 45 = -60