Réponse:
3/8 - 4/5 = - 17/40
21/72 X 8/7 = 1/3
- 4/3 + 8/9 = - 4/9
9/10 - -2/5 - 3/2 = - 1/5
-11/22 X 2/-10 X -5/3 = - 1/6
49/-5 le tout / - 7 = 7/5
