1/12+1/4=?,1/3-1/6=,3/20+3/4,7/9-2/3,1/4+1/5,2/5+4/15,11/20-5/12,8/9+7/54,5/6-17/21,3/16+1/24,5/6-22/27 пж помогите срочно!!!!!

1/12+1/4=1/3 ...

1/3-1/6=1/6....

3/20+3/4=11/20....

7/9-2/3=2/9

1/4+1/5=9/20

2/5+4/15=9/15

8/9+7/54=41/54