Непонятно одно. 8−(3
20
13
�
 −2):
25
9
�
 −2
8
7
�
 �.

8 – (3(13/20) – 2)/(9/25) – 2(7/8)

3(13/20) – 2 = 73/20 – 40/20 = 33/20.

(33/20) /(9/25) = (33/20) * (25/9) = 55/12.

8 – 55/12 = 96/12 – 55/12 = 41/12.

41/12 – 2(7/8) = 82/24 – 69/24 = 13/24.

Ответ: 13/24.