3/4 + 2/3
3/10 + 2/15
4/9 + 1/6
7/15 + 3/40

6/7 - 2/3
11/12 - 5/6
7/12 - 3/8
9/14 - 19/35​

Пошаговое объяснение:

3/4 + 2/3=9+8/12=17/12

3/10+2/15=9+4/30=13/30

4/9 + 1/6=8+3/18=11/18

7/15 + 3/40= 56+9/120=65/120

6/7 - 2/3 =18-14/21=4/21

11/12 - 5/6=11-10/12=1/12

7/12 - 3/8=14-9/24=5/24

9/14 - 19/35=45-38/70=7/70