Verified answer

Ответ:

Пошаговое объяснение:

№1

2/3 : (4/9х - 4/9) + 1/20 = 4/5

2/3 : (4/9х - 4/9) = 4/5 - 1/20

2/3 : (4/9х - 4/9) = 16/20 - 1/20

2/3 : (4/9х - 4/9) = 15/20

4/9х - 4/9 = 2/3 : 15/20

4/9х - 4/9 = 2/3 * 20/15

4/9х - 4/9 = 40/45

4/9х - 4/9 = 8/9

4/9х = 8/9 + 4/9

4/9х = 12/9

х = 12/9 : 4/9

х = 12/9 * 9/4

х = 12/4

х = 3

№2

5/7 : (6/7х + 3/7) - 1/2 = 1/6

5/7 : (6/7х + 3/7) = 1/6 + 1/2

5/7 : (6/7х + 3/7) = 1/6 + 3/6

5/7 : (6/7х + 3/7) = 4/6

6/7х + 3/7 = 5/7 : 4/6

6/7х + 3/7 = 5/7 * 6/4

6/7х + 3/7 = 30/28

6/7х = 30/28 - 3/7

6/7х = 30/28 - 12/28

6/7х = 18/28

х = 18/28 : 6/7

х = 18/28 * 7/6

х = 3/4 * 1/1

х = 3/4

№3

3/4 : (5/8х - 1/2) - 1/8 = 1/4

3/4 : (5/8х - 1/2) = 1/4 + 1/8

3/4 : (5/8х - 1/2) = 2/8 + 1/8

3/4 : (5/8х - 1/2) = 3/8

5/8х - 1/2 = 3/4 : 3/8

5/8х - 1/2 = 3/4 * 8/3

5/8х - 1/2 = 1/1 * 2/1

5/8х - 1/2 = 2/1

5/8х - 1/2 = 2

5/8х = 2 + 1/2

5/8х = 2. 1/2

х = 2. 1/2 : 5/8

х = 5/2 * 8/5

х = 40/10

х = 4