Verified answer

Пошаговое объяснение:

А)

5 * (1 1/2 - 0,2х) = 1

1 1/2 - 0,2х = 1 : 5

1 1/2 - 0,2х = 1/5

0,2х = 1 1/2 - 1/5

2/10х = 1 5/10 - 2/10

2/10х = 1 3/10

2/10х = 13/10

х = 13/10 : 2/10

х = 13/10 * 10/2

х = 13/2

х = 6 1/2 или 6,5

Б)

3/7х - 1/21х = 2 2/7

9/21х - 1/21х = 2 2/7

8/21х = 16/7

х = 16/7 : 8/21

х = 16/7 * 21/8

х = 2/1 * 3/1

х = 6/1

х = 6