Bonjour
A=5/4+7/6
A = (5x 3) / (4 x 3) + (7 x 2) / (6 x 2)
A = 15/12 + 14/12
A = 29/12
B=7/12-3/4
B = 7/12 - (3 x 3) / (4 x 3)
B = 7/12 - 9/12
B = - 2/12
B = (2 x - 1) / (2 x 6)
B = - 1/6
C=8/15-1/8-1
C = (8 x 8) / (15 x 8) - (1 x 15) / (8 x 15) - (1 x 120) / (1 x 120)
C = 64/120 - 15/120 - 120/120
C = 64/120 - 135/120
C = - 71/120
D=3-7/6-1/2
D = (3 x 6) / (1 x 6) - 7/6 - (1 x 3) / (2 x 3)
D = 18/6 - 7/6 - 3/6
D = 18/6 - 10/6
D = 8/6
D = (2 x 4) / (2x 3)
D = 4/3
E=21-12-75-24+37-23
E = 21 + 37 - 12 - 75 - 23 - 24
E = 58 - 134
E = - 76
F=54-(-71)+(+23)-(+15)+(-64)
F = 54 + 71 + 23 - 15 - 64
F = 148 - 49
F = 99.
