svp je veux la corréction svp de ces exercices

C= 100+25/100-25

C =125/75

B=5/3-1/2+4/7

B=70/42-21/42+24/42

B=70-21+24/42

B= 73/42

A=1/3+1/4+1/5

A= 20/60+15/60+12/60

A= 20+15+12/60

A= 47/60