Ответ:

Пошаговое объяснение:

1.

4/10 = 2/5

2/5*7/12 = 7/30

2/11 : 15/11 = 2/11 * 11/15 = 2/15

7/30 + 2/15 = 7/30 + 4/30 = 11/30

2.

1  5/6 - 1 3/4 = 20/24 - 18/24 = 2/24 = 1/12

2,4 = 2 4/10 = 12/5

1/12 = 12/5 = 1/5

3.

6,5 = 6 5/10 = 6 1/2

8 3/4 - 6 1/2 = 2 1/4 = 9/4

9/4 : 1/8 = 9/4 * 8/1 = 18

4.

2 2/9 = 20/9

0,45 = 45/100 = 9/20

20/9*9/20 = 1

3 1/3 +1 = 4 1/3

5.

2,75 = 2 75/100 = 2 15/20 = 2 3/4

2 3/4 - 1 1/6 = 1 14/24 = 1 7/12 = 19/12

19/12 : 3/4 = 19/12 * 4/3 = 19/9 = 2 1/9