Ответ:

Пошаговое объяснение:

4/9 : 16/27 = 4/9 * 27/16 = 1/1 * 3/4 = 1 * 3 / 1 * 4 = 3/4

5 : 5/11 = 5 * 11/5 = 1 * 11/1 = 1/1 * 11/1 = 1 * 11 / 1 * 1 =  11/1 = 11

1/4 * 8/9 = 1/1 * 2/9 = 1 * 2 / 1 * 9 = 2/9