Sagot :

Vins

Réponse :

bonjour

A =  ( 2/3 + 5/7 ) / ( 2/3 x 5/7 )

A = ( 14/21 + 15/21 )  / 10/21

A = 29/21 : 10/21

A = 29/21 x 21/10

A = 29/10 = 2.9

B = ( 5 + 3/4 - 1/3 ) : ( 5 - 3/4 + 1/3 )

B =  ( 60 /12 + 9/12 - 4/12 ) : ( 60/12 - 9/12 + 4/12 )

B = 65/12 : 55/12

B = 65/12 x 12/55

B =  65/55 = 13/11

C = ( 1/5 - 3/4 x 2/3 ) : ( 1/5 - 3/4 ) x 2/3

C = ( 1/5 - 6/12 ) : ( 4/20 - 15/20 ) x 2/3

C =  ( 12/60 - 30/60 ) : ( - 11/20 x 2/3 )

C = - 18/60  : - 22/60

C = - 18/60 x - 60/22

C = 18/22 = 9 /11

Explications étape par étape :

mariejoe57

Réponse :

bonjour

Explications étape par étape :

A= (2/3+5/7)  / 2/3x5/7)

=14/21+15/21  / 10/21

==29/21  / 10/21

=29/21 x 21/10

=29/10

=2.9

B=[5+3/4-1/3]  / [5-3/4+1/3]

=60/12+9/12-4/12  / 60/12-9/12+4/12

=65/12  /  55/12

=65/12 x 12/55

=65/55

=13/11

c=[1/5-3/4x2/3]  / (1/5-3/4)x2/3

=[1/5-1/2) /  (4/20 -15/20) x2/3

=(2/10 - 5/10)  / (-11/20 x 2/3)

=-3/10 / -22/60

=-3/10 /-11/30

= -3/10x-30/11

=9/11