Ответ:

|5x-2|=4

5x-2 = ±4

5x-2 = 4

5x = 6 | : 5

x = 1.2

5x-2 = -4

5x = -2 | : 5

x = -0.4

|-5x-2| = -4

x - не существует

|3 - 7x| = 2

3 - 7x = ±2

7x = 1 | :7

x = 1/7

7x = 5 | :7

x = 5/7

|101x + 4| = -1

x - не существует