Bonjour,
C = - 390/156 + 3
C = (78 x - 5) / (78 x 2) + (3 x 2) / (1 x 2)
C = 5/2 + 6/2
C = 11/2
D = 4/5 - (7/10 - 5/6)
D = (4 x 6) / (5 x 6) - [(7 x 3) / (10 x 3) - (5 x 5) / (6 x 5)]
D = 24/30 - (21/30 - 25/30)
D = 24/30 - (- 4/30)
D = 24/30 + 4/30
D = 28/30
D = (2 x 14) / (2 x 15)
D = 14/15.
