Bonjour
A = - 13/8 + 7/16
A = (- 13 x 2) / (8 x 2) + 7/16
A = - 26/16 + 7/16
A = - 19/16
B = 7/35 + 8/15
B = (7 x 3) / (35 x 3) + (8 x 7) / (15 x 7)
B = 21/105 + 56/105
B = 77/105
B = (7 x 11) / (7 x 15)
B = 11/15
C = 11/26 - 5/39
C = (11 x 3) / (26 x 3) - (5 x 2) / (39 x 2)
C = 33/78 - 10/78
C = 23/78
D = 7/11 + 4/25
D = (7 x 25) / (11 x 25) + (4 x 11) / (25 x 11)
D = 175/275 + 44/275
D = 219/275
E = 3/12 - 5/18 + 1
E = (3 x 3) / (12 x 3) - (5 x 2) / (18 x 2) + (1 x 36) / (1 x 36)
E = 9/36 - 10/36 + 36/36
E = 35/36
F = - 5/4 + 2/3 - - 7/5
F = (- 5 x 15) / (4 x 15) + (2 x 20) / (3 x 20) + (7 x 12) / (5 x 12)
F = - 75/60 + 40/60 + 84/60
F = 49/60.
