13 47/66.
Пошаговое объяснение:
20 2/3 + (3 - 2/11) : 5 1/6 - 7,5 = 20 2/3 + 2 9/11 : 5 1/6 - 75/10 = 20 2/3 + 31/11 : 31/6 - 15/2 = 62/3 + 31/11 * 6/31 - 15/2 = 62/3 + 6/11 - 15/2 = 20 44/66 + 36/66 - 495/66 = 20 - 415/66 = 18 - 283/66 = 13 47/66.
