Ответ:

1/2

Пошаговое объяснение:

1) 2 - 1 9/11 = 1 11/11 - 1 9/11 = 2/11

2) 3 1/7 * 2/11 = 22/7 * 2/11 = 2/7 * 2/1 = 4/7

3) 4/7 : 8/21 = 4/7 * 21/8 = 1/1 * 3/2 = 3/2 = 1 1/2

4) 2 - 1 1/2 = 1 2/2 - 1 1/2 = 1/2

Ответ:

Пошаговое объяснение:

2 - 3 1/7 * ( 2 - 1 9/11) : 8/21 = 1/2

1) 2 - 1 9/11 = 1 11/11 - 1 9/11 = 2/11

2) 3 1/7 * 2/11 = 22/7 * 2/11 = 4/7

3) 4/7 : 8/21 = 4/7 * 21/8 = 3/2 = 1 1/2

4) 2 - 1 1/2 = 1 2/2 - 1 1/2 = 1/2