Comment calculer cela svp ???

24/35 - [(3/5 - 9/7)]/ (2 -11/4)
= 24/35 - [21/35 -45/35] / (8/4 -11/4)
= 24/35 - [-24/35] / (-3/4)
= 24/35 - (-24/35 X -4/3)
= 24/35 - (96/105)
= 24/35 - (32/35)
= -8/35