-8+9-10+11-12+13-14+15th
А) -8 + 9 - 10 + 11 - 12 + 13 - 14 + 15 = 4 б) 9 - 10 + 11 - 12 + 13 - 14 + 15 - 16 = -4 в) -1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 = -55