Ответ:

1) 9x = 2/5

x = 2/5 ÷ 9

х = 2/45

2) 3x = 2 1/7

x = 2 1/3 ÷ 3

x = 7/9

3) 1/2x = 3

x = 3 ÷ 1/2

x = 6

4) 3/4x = 1/2​

x = 1/2 ÷ 3/4

x = 4/6 = 2/3