Ответ:

Пошаговое объяснение:

1.

(3/4 + 1/20) * 1/2 = (15/20 + 1/20) * 1/2 = 16/20 * 1/2 = 16/40 = 2/5

3.

(7 3/5 - 2 4/15) * 9/32 =

(7 9/15 - 2 4/15) * 9/32 =

5 5/15 * 9/32 = 5 1/3 * 9/32 = 16/3 * 9/32 = 1/1 * 3/2 = 1 1/2

5.

(5 1/2 + 2 3/5) * 5/9 =

(5 5/10 + 2 6/10) * 5/9 =

7 11/10 * 5/9 = 8 1/10 * 5/9 = 81/10 * 5/9 = 9/2 * 1/1 = 9/2 = 4 1/2