Aidez moi je n'y arrive pas

1er exercice
3/4/9 = 3/4 X 1/9 = 3/36 = 1/12

3/4/9 = 3 X 9/4 = + 27/4

1/1/2 -1/3 = 1/3/6 -2/6 = 1/ 1/6 = 1 X 6/1 = 6

5 -4/3/5 +4/3 = 15/3 -4/3 / 15/3 +4/3 = 11/3 /19/3 = 11/3 X 3/19 = 33/57