Ответ:

1. 17/20

2. 23/55

3. 17/32

4. 13/28

5. 7/30

6. 13/24

7. 1/100

8.  29/168

9. 1/24

10. 23/48

11. 5/12

12. 1/9

Пошаговое объяснение:

1/4+3/5=17/20=0,85

9/11-2/5=23/55

13/16-9/32=17/32

3/28+5/14=13/28

14/15-7/10=7/30

3/8+1/6=13/24

9/25-7/20=1/100=0,01

37/42-17/24=29/168

11/24-3/6=-1/24

9/16+7/24-3/8=41/48-3/8=-121/48

1/3-1/6+1/4=5/12

2/5+4/15-5/9=1/9