Bonjour pouvez m'aidez svp pour l'exercice 2 (urgent)

Bonjour,

A = 1/9 + 3/9
A = 4/9

B = - 4/12 + 2/12
B = - 2/12
B = 2 x - 1 / 2 x 6
B = - 1/6

C = - 20/12 + 2/3
C = - 20/12 + 2 x 4 / 3 x 4
C = - 20/12 + 8/12
C = - 12/12
C = - 1

D = 1/3 + 1/6 - 1/9
D = 1 x 6 / 3 x 6 + 1 x 3 / 6 x 3 - 1 x 2 / 9 x 2
D = 6/18 + 3/18 - 2/18
D = 9/18 - 2/18
D = 6/18
D = 6 x 1 / 6 x 3
D = 1/3

E = 3/8 - (- 9/3)
E = 3/8 + 9/3
E = 3 x 3 / 8 x 3 + 9 x 8 / 3 x 8
E = 9/24 + 72/24
E = 81/27
E = 3 x 27 / 3 x 8
E = 27/8