bjr

A = 4/7 + 3/4 + 2/7 + 5/4 + 1/7

tu vas donc déplacer les termes pour que les dénominateurs identiques soient identiques

A = (4/7 + 2/7 + 1/7) + (3/4 + 5/4)

A = 7/7 + 8/4 = 1 + 2 = 3

B = 4/3 + 3/5 + 7/3 + 2/5 + 1/3

B = (4/3 + 7/3 + 1/3) + (3/5 + 2/5)

B = 12/3 + 5/5 = 4 + 1 = 3

C = 5/12 + 5/3 + 2/12 + 2/3 + 1/12

C = (5/12 + 2/12 + 1/12) + (5/3 + 2/3)

C = 8/12 + 7/3

C = 2/3 + 7/3 = 9/3

D = 5/2 + 3/8 + 7/2 + 6/8 - 6

D = (5/2 + 7/2) + (3/8 + 6/8) - 6

D = 12/2 + 9/8 - 6

D = 6 - 6 + 9/8 = 9/8

Réponse :

Bonjour,

Pour cet exercice, nous devons regrouper les fractions ayant un dénominateur commun :

A = 4/7 + 3/4 + 2/7 + 5/4 + 1/7

A = 4/7 + 2/7 + 1/7 + 3/4 + 5/4

A = 7/7 + 8/4

A = 1 + 2

A = 3

B = 4/3 + 3/5 + 7/3 + 2/5 + 1/3

B = 4/3 + 7/3 + 1/3 + 3/5 + 2/5

B = 12/3 + 5/5

B = 4 + 1

B = 5

C = 5/12 + 5/3 + 2/12 + 2/3 + 1/12

C = 5/12 + 2/12 + 1/12 + 5/3 + 2/3

C = 8/12 + 7/3

C = 2/3 + 7/3

C = 9/3

C = 3

D = 5/2 + 3/8 + 7/2 + 6/8 - 6

D = 5/2 + 7/2 + 3/8 + 6/8 - 6

D = 12/2 + 9/8 - 6

D = 6 + 9/8 - 6

D = 9/8

D = 1,125