Ответ:

Пошаговое объяснение:

1.

1) 5/6 * 9/15 = 1/2 * 3/3 = 3/6 = 1/2

2) 5/12 * 4/15 = 1/3 * 1/3 = 1/9

3) 1/2 - 1/9 = 9/18 - 2/18 = 7/18

2.

1) 7/18 * 9/14 = 1/2 * 1/2 = 1/4

2) 1/3 * 6/7 = 6/21 = 2/7

3) 1/4 + 2/7 = 7/28 + 8/28 = 15/28

3.

1) 9/20 * 2/3 = 3/10 * 1/1 = 3/10

2) 5/14 * 7/25 = 1/2 * 1/5 = 1/10

3) 3/10 + 1/10 = 4/10 = 2/5

4.

1) 3. 3/4 * 2/5 = 15/4 * 2/5 = 3/2 * 1/1 = 3/2 = 1. 1/2

2) 3. 6/25 * 5/27 = 81/25 * 5/27 = 3/5 * 1/1 = 3/5

3) 1. 1/2 - 3/5 = 1. 5/10 - 6/10 = 15/10 - 6/10 = 9/10

5.

1) 2. 2/5 * 5/6 = 12/5 * 5/6 = 12/6 = 2

2) 3/4 * 1. 2/3 = 3/4 * 5/3 = 5/4 = 1. 1/4

3) 2 - 1. 1/4 = 1. 4/4 - 1. 1/4 = 3/4

6.

1) 1. 17/28 * 7/9 = 45/28 * 7/9 = 5/4 * 1/1 = 5/4 = 1. 1/4

2) 14/25 * 5/7 = 2/5 * 1/1 = 2/5

3) 1. 1/4 + 2/5 = 1. 5/20 + 8/20 = 1. 13/20