Sagot :
Bonjour
A = 4/5 + 7/8
A = (4 x 8) / (5 x 8) + (7 x 5) / (8 x 5)
A = 32/40 + 35/40
A = 67/40
B = 6/5 - 1/20
B = (6 x 4) / (5 x 4) - 1/20
B = 24/20 - 1/20
B = 23/20
C = - 36/5 x - 25/12
C = 900/60
C = (60 x 15) / (60 x 1)
C = 15
D = 3/8 : 9/16
D = 3/8 x 16/9
D = 48/72
D = (24 x 2) / (24 x 3)
D = 2/3.