7) 13/29-2/29=11/29

8) 11/51+13/51=24/51=8/17

9) 17/72-13/72=4/72=1/18

10) 32/55+23/55=55/55=1

11) 5/33+6/33=11/33=1/3

12) 13/48-11/48=2/48=1/24

Ответ:

7) 11/29

8) 24/51=8/17

9) 4/72 = 1/18

10) 55/55 = 1

11) 11/33 = 1/3

12) 2/48 = 1/24