Пошаговое объяснение:

1) 11/39 : 6/13 = 11/39 * 13/6 = 11/3 * 1/6 = 11/18

2) 11/18 : 3 8/12 = 11/18 : 44/12 = 11/18 * 12/44 = 1/3 * 2/4 = 2/12 = 1/6

3) 1/6 * 3 5/7 = 1/6 * 26/7 = 1/3 * 13/7 = 13/21

Відповідь: (11/39 : 6/13) : 3 8/12 × 3 5/7 = 7/156

Кроки розв'язання:

1) 11/39 : 6/13 = 11/39 × 13/6 = 11/3 × 1/6 = 11/18

2) 3 8/12 × 3 5/7 = 44/12 × 26/7 = 11/3 × 26/7 = 286/21 = 13 13/21

3) 11/18 : 13 13/21 = 11/18 : 284/21 = 11/18 × 21/286 = 1/6 × 7/26 = 7/156