Ответ:57 − 7 − 1 = 50 − 1 = 49.11 − 7 = 4.19 + (9 − 8) = 19 + 1 = 20.20 − (2 + 8) = 20 − 10 = 10.14 − 9 = 5.5 + 8 = 13.76 − 6 − 1 = 70 − 1 = 69.6 + 7 = 13.