Bonjour excusez-moi mais pouvais vous m’aidez pour se devoirs niv5eme merci d’avance

Bonsoir,

A = 11/9 - 7/9

A = 4/9

B = 7/5 + 3/20

B = (7 x 4) / (5 x 4) + 3/20

B = 28/20 + 3/20

B = 31/20

C = 3 + 2/5

C = (3 x 5) / (1 x 5) + 2/5

C = 15/5 + 2/5

C = 17/5

D = 5/4 - 1/2

D = 5/4 - (1 x 2) / (2 x 2)

D = 5/4 - 2/4

D = 3/4

E = 3/4 + 1/2 + 5/8

E = (3 x 2) / (4 x 2) + (1 x 4) / (2 x 4) + 5/8

E = 6/8 + 4/8 + 5/8

E = 15/8

F = 3/4 - 2/3

F = (3 x 3) / (4 x 3) - (2 x 4) / (3 x 4)

F = 9/12 - 8/12

F = 1/12

Bonsoir,

Effectue les opérations suivantes

Méthode : on met les termes au même dénominateur si besoin puis on simplifie.

A = 11/9 - 7/9 = (11-7)/9 = 4/9

B = 7/5 + 3/20 = (7×4)/(5×4) + 3/20

B = 28/20 + 3/20 = 31/20

C = 3 + 2/5 = 15/15 + 2/5 = 17/5

D = 5/4 - 1/2 = 5/4 - (1×2)/(2×2)

D = 5/4 - 2/4 = 3/4

E = 3/4 + 1/2 + 5/8 = (3×2)/(4×2) + (1×4)/(2×4) + 5/8

E = 6/8 + 4/8 + 5/8 = (6+4+5)/8 = 15/8

F = 3/4 - 2/3 = (3×3)/(4×3) - (2×4)/(3×4)

F = 9/12 - 8/12 = 1/12

Bonne soirée !