Ответ:12 − 5 + 7 = 7 + 7 = 14.16 − 9 + 8 = 7 + 8 = 15.8 + 7 − 9 = 15 − 9 = 6.13 − (16 − 8) = 13 − 8 = 5.15 + (11 − 7) = 15 + 4 = 19.16 − (18 − 9) = 16 − 9 = 7.