je n'y arrive svp :):):):):)(:;)(;););););)​

Bonjour,

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

A = 2/3 + 20/21

A = (2 x 7) / (3 x 7) + 20/21

A = 14/21 + 20/21

A = 34/21.

B = 1/5 - 7/5 x 2/3

B = 1/5 - 14/15

B = (1 x 3) / (5 x 3) - 14/15

B = 3/15 - 14/15

B = - 11/15

C = 7/30 - 4/3 : 5/2

C = 7/30 - 4/3 x 2/5

C = 7/30 - 8/15

C = 7/30 - (8 x 2) / (15 x 2)

C = 7/30 - 16/30

C = - 9/30

C = (3 x - 3) / (3 x 10)

C = - 3/10.

D = (4 - 1/3) + 5/4

D = [(4 x 3) / (1 x 3) - 1/3] + 5/4

D = (12/3 - 1/3) + 5/4

D = 11/3 + 5/4

D = (11 x 4) / (3 x 4) + (5 x 3) / (4 x 3)

D = 44/15 + 15/12

D = 59/12

E = 8/7 + 5/7 x 1/15

E = 8/7 + 5/105

E = (8 x 3) / (7 x 3) + (5 x 1) / (5 x 21)

E = 24/21 + 1/21

E = 25/21.

F = 4/9 - 8/9 : 16/5

F = 4/9 - 8/9 x 5/16

F = 4/9 - 40/144

F = (4 x 2) / (9 x 2) - (8 x 5) / (8 x 18)

F = 8/18 - 5/18

F = 3/18

F = (3 x 1) / (3 x 6)

F = 1/6.