Bonjour
A= 4sur9 - 7sur27
A = (4 x 3) / (9 x 3) - 7/27
A= 12/27 - 7/27
A = 5/57
B= 6sur5 - 8sur45
B = (6 x 9) / (5 x 9) - 8/45
B = 54/45 - 8/45
B = 46/45
C= 6sur5- 7sur30
C = (6 x 6) / (5 x 6) - 7/30
C = 42/30 - 7/30
C = 35/30
C = (5 x 7) / (5 x 6)
C = 7/6
D= 8sur7 - 4sur35
D = (8 x 5) / (7 x 5) - 4/35
D = 40/35 - 4/35
D = 36/35.
