Bonjour
C = 7/5 - 4/5 x 25/8
C = 7/5 - 100/40
C = (7 x 8) / (5 x 8) - 100/40
C = 56/40 - 100/40
C = - 44/40
C = (4 x - 11) / (4 x 10)
C = - 11/10
D = 7/8 + 11/24 - 4/7
D = (7 x 21) / (8 x 21) + (11 x 7) / (24 x 7) - (4 x 24) / (7 x 24)
D = 147/168 + 77/168 - 96/168
D = 128/168
D = (8 x 16) / (8 x 21)
D = 16/21
E = 25/13 : 15/21 - 7/3
E = 25/13 x 21/15 - 7/3
E = 525/195 - 7/3
E = 525/195 - (7 x 65) / (3 x 65)
E = 525/195 - 455/195
E = 70/195
E = (5 x 14) / (5 x 39)
E = 14/39.
