Réponses

2014-09-11T06:11:57+02:00

Bonjour


A  = 9/14 - 2/7 x 5

 A   = 9/14 - 10/7

 A   = 9/14 - 20/14

 A  = -11/14


B = 8/3 -5/3 : 20/21

B = 8/3 - 5/3 x 21/20

B = 8/3 - 105/60

B = 160/60 - 105/60

B = 55/60

B = 11/12


C = 1 - (2/3 + 1/4)

C = 1 - (8/12 + 3/12)

C = 1 - 11/12

C = 12/12 - 11/12

C = 1/12

D = (3-5/2) / (1+1/5)

D = (6/2 - 5/2) / (5/5 + 1/5)

D = (1/2) / (6/5)

D = 1/2 x 5/6

D = 5/12 



2014-09-11T06:27:30+02:00
A = 9/14 - 2/7 x 5
A = 9/14 - 10/7
A = 9/014 - 10 x 2 / 7 x 2
A = 9/14 - 20/14
A = - 11/14

B = 8/3 - 5/3 : 20/21
B = 8/3 - 5/3 x 21/20
B = 8/3 - 105/60
B = 8 x 20 / 3 x 20 - 105/60
B = 160/60 - 105/60
B = 55/60
B = 5 x 11 / 5 x 12
B = 11/12

C = 1 - (2/3 + 1/4)
C = 1 - (2 x 4 / 3 x 4 + 1 x 3 / 4 x 3)
C = 1 - (8/12 + 3/12)
C = 1 - 11/12
C = 1 x 12 / 1 x 12 - 11/12
C = - 1/12


D = (3 - 5/2) / (1 + 1/5)
D = (3 x 2 / 1 x 2 - 5/2) / (1 x 5 / 1 x 5 + 1/5)
D = (6/2 - 5/2) / (5/5 + 1/5)
D = (1/2) / (6/5)
D = 1/2 x 5/6
D = 5/12


je te remercie d'avoir pris le temps de m'aider
Je t'en prie