Ответ:

Пошаговое объяснение:

8/15 : 20/21 = 8/15 * 21/20 = 14/25

21/22 : 7/18 = 21/22 * 18/7 = 27/11 = 2 5/11

39/43 : 13/43 = 39/43 * 43/13 = 3

44/45 : 11/18 = 44/45 * 18/11 = 8/5 = 1 3/5