(73 + 7) + 6 = 80 + 6 = 86
73 - (7 + 6) = 73 - 13 = 60
73 - 7 + 6 = 66 + 6 = 72
73 + 7 - 6 = 80 - 6 = 74
Ответ: (73 + 7) + 6 = 86; 73 - (7 + 6) = 60; 73 - 7 + 6 = 72; 73 + 7 - 6 = 74