1) x + 7/12 = 3/4

x = 3/4 - 7/12

x = 9/12 - 7/12

x = 2/12

x = 1/6

Ответ: 1/6

2) x - 1/6 = 1/9

x = 1/9 + 1/6

x = 2/18 + 3/18

x = 5/18

Ответ: 5/18