2) 1/x - 1/7x =2/7
3) 1/4x + 1/x=5/16

2) x=3

3) x=4

Пошаговое объяснение:

2) 1/x-1/7x=2/7

7-1=2x

6=2x

x=6:2

x=3

3) 1/4x+1/x=5/16

4+16=5x

20=5x

x=20:5

x=4

1) 1/x -1/7x = 2/7

6/7x = 2/7

14x=42

x=3

2) 1/4x + 1/x = 5/16

5/4x = 5/16

4x = 16

x = 4