здравствуй.

2 1/4 = 2 25/100 = 2,25

5 1/2 = 5 5/10 = 5.5

7 3/5 = 7 6/10 = 7.6

9 7/20 = 9 35/100 = 9.35

11 2/25 = 11 8/100 = 11.08

4 11/50 = 4 22/100 = 4.22

удачи в учёбе.