срочно дам 100
..........​

Ответ:

Пошаговое объяснение:

А)

7/18 + 1/9 = 7/18 + 2/18 = 9/18 = 1/2

Б)

1/2 - 3/8 = 4/8 - 3/8 = 1/8

С)

1/21 - 9/14 = 2/42 - 27/42 = -25/42

Д)

5/42 - 8/21 + 1/14 = 5/42 - 16/42 + 3/42 = (5-16+3)/42 = -8/42 = -4/21

Е)

13/24 : 26/33 + 5/12 = 13/24 * 33/26 + 5/12 = 1/8 * 11/2 + 5/12 = 11/16 + 5/12 = 33/48 + 20/48 = 53/48 = 1. 5/48

Ф)

7/15 - 2/3 * 5/6 = 7/15 - 10/18 = 7/15 - 5/9 = 21/45 - 25/45 = -4/45