calculer sous forme de fraction simplifiée.

A = 2/3 + 5/9
A = 2 x 3 / 3 x 3 + 5/9
A = 6/9 + 5/9
A = 11/9

B = 2 + 5/9
B = 2 x 9 / 1 x 9 + 5/9
B = 18/9 + 5/9
B = 23/9

C = 2 + 2/3 + 5/9
C = 2 x 9 / 1 x 9 + 2 x 3 / 3 x 3 + 5/9
C = 18/9 + 6/9 + 5/9
C = 29/9

E = 2/3 x 9/8
E = 18/24
E = 6 x 3 / 6 x 4
E = 3/4

D = 5/9 (1 + 2/3)
D = 5/9 (1 x 3 / 1 x 3 + 2/3)
D = 5/9 (3/3 + 2/3)
D = 5/9 x 5/3
D = 25/27