svp c urgent pr demain merci bcccpp :)

A = 3 + 5/4 x (2-1/5)
A = 3 +5/4 x (10/5 - 1/5)
A = 3 + 5/4 x 9/5
A = 3 + 9/4
A = 12/4 + 9/4
A = 21/4

B = (11/6 - 3/8) : (4/9 + 2/3)
B = (44/24 - 9/24) : (4/9 + 6/9)
B = 35/24 : 10/9
B = 35/24 x 9/10
B = (5 x 7/3 x 8) x (3 x 3/5 x 2)
B = 21/16

C = 7/4 - 3/4 x 8/9
C = 7/4 - 3/4 x (4 x 2/3 x 3)
C = 7/4 - 2/3
C = 21/12 - 8/12
C = 13/12

D = (1 - 2/3) : (1 + 2/3)
D = (3/3 - 2/3) : (3/3 + 2/3)
D = 1/3 : 5/3
D = 1/3 x 3/5
D = 1/5

J'espère t'avoir aidé(e)! :)