1) 3/12+25/30 2) 10/24-21/54
3)30/54+22/30
4)28/40-10/75
5)12/27+14/21
6)14/24-15/40
7)12/18-5/60
8)4/24+3/36.

1) 1 1/12

2) 1/36

3) 1 13/45

4) 17/30

5) 1 1/9

6) 5/24

7) 7/12

8) 1/4

Пошаговое объяснение:

3/12 + 25/30 = 1/4 + 5/6 = 3/12 + 10/12 = 13/12 = 1 1/12

10/24 - 21/54 = 5/12 - 7/18 = 15/36 - 14/36 = 1/36

30/54 + 22/30 = 5/9 + 11/15 = 25/45 + 33/45 =58/45 = 1 13/45

28/40 - 10/75 = 7/10 -2/15 = 21/30 - 20/30 =1/30

12/27 +14/21 = 4/9 + 2/3 = 4/9 + 6/9 = 10/9 = 1 1/9

14/34 - 15/40 = 7/12 - 3/8 = 14/24 - 9/24 = 5/24

12/18 - 5/60 = 2/3 - 1/12 = 8/12 - 1/12 = 7/12

4/24 +3/36 = 1/6 + 1/12 = 2/12 + 1/12 = 3/12 = 1/4