Ответ:

Пошаговое объяснение:

N 1

1) 2. 3/4 : 5. 1/2 = 11/4 : 11/2 = 11/4 * 2/11 = 2/4 = 1/2

2) 3. 1/3 * 1/2 = 10/3 * 1/2 = 10/6 = 5/3 = 1. 2/3

Ответ: 1. 2/3

N 2

1) 6. 3/8 * 1. 7/17 = 51/8 * 24/17 = 3/1 * 3/1 = 9/1 = 9

2) 2. 3/8 : 1. 1/4 = 19/8 : 5/4 = 19/8 * 4/5 = 19/2 * 1/5 = 19/10 = 1. 9/10

3) 9 - 1. 9/10 = 8. 10/10 -

1. 9/10 = 7. 1/10

4) 7. 1/10 + 2/5 = 7. 1/10 + 4/10 = 7. 5/10 = 7. 1/2

Ответ: 7. 1/2

N 3

a)

4/15 : х = 2/5

х = 4/15 : 2/5

х = 4/15 * 5/2

х = 20/30

х = 2/3

Ответ: 2/3

б)

2/15у + 3/4 = 5/6

2/15у = 5/6 - 3/4

2/15у = 10/12 - 9/12

2/15у = 1/12

у = 1/12 : 2/15

у = 1/12 * 15/2

у = 1/4 * 5/2

у = 5/8

Ответ: 5/8