Ответ:

Пошаговое объяснение:

А)

2. 1/7 * 3. 1/9 = 15/7 * 28/9 = 5/1 * 4/3 = 20/3 = 6. 2/3

Б)

3/7 * 7/9 = 1/1 * 1/3 = 1/3

В)

5/8 * 1. 13/15 * 2. 2/7 =

5/8 * 28/15 * 16/7 =

1/2 * 7/3 * 16/7 =

7/6 * 16/7 = 1/3 * 8/1 = 8/3 =

2. 2/3