Réponse :

b) B = (1 - 1/3) x 9/8 = (3/3 - 1/3) x 9/8 = 2/3) x 9/8 = 2 x 3 x 3/3 x 2 x 4 = 3/4

c) C = 2/3 + 1/3 : 8/9   ici l'ordre de priorité de calcul est la division

       = 2/3  + 3/8 = 16/24 + 9/24 = 25/24

d)  D  est incompréhensible

Explications étape par étape

1/3 : 8/9 = 1 x 9/3 x 8 = 1 x 3 x 3/3 x 8 = 3/8

Bonjour !

B = (1-1/3)x9/8

B = (3/3-1/3)x9/8

B = 2/3x9/8 = 18/24

B= 18:6/24:6 = 3/4

C = 2/3+1/3 : 8/9

C = 2/3 + 1/3x9/8

C = 2/3 + 9/24

C = 2x8/3x8 + 9/24

C = 16/24 + 9/24

C = 25/24

D = (2/3+1/3) : 8/9

D = 3/3 x 9/8

D = 27/24

D = 27:3/24:3

D = 9/8

Et si D = (2/3 : 1/3) : 8/9

D = (2/3x3/1) : 8/9

D= 6/3 x 9/8 = 54/24

D = 54:6/24:6

D = 9/4

Bon courage.