cest juste l'exercice 2 svp urgent pour demain a 8h !!!!! dm a rendre stp repder moi

bonjour

1/2 +2/3 = 3/6 +4/6 = 7/6
-3/11 +1/2 = -6/22 + 11/22 = 5/22
3/5 -2/7 = 21/35 - 10/35 = 11/35
-5/7 - 2/3 = - 15/21 - 14/21 = - 29/21
19/20 -( -4/30) = 57/60 - ( - 8/60) = 57/60 + 8/60 = 63/60  = 21/20
1/-2 - ( -5/3) = - 3/6 - ( -10/6) = -3/6 + 10/6 = 7/6
-21 /-16 + 25/ -24 = -63/-48 + 50/-48 = 63/48 - 50/48 = 13/48
14/-10 - ( -10/14) =  - 196/140 + 100/140 = - 96/140 = -24/35