Bonjour !

A = 5/3 + 4/5 * 1/3

= 5/3 + 4/15

= 5*5/3*5 + 4/15

= 25/15 + 4/15

= 29/15

B = 7/5 * 4/3 - 1/7 * 3/5

= 28/15 - 3/35

= 28*7/15*7 - 3*3/35*3

= 196/105 - 9/105

= 187/105

C = 1/3 - (3/4 + 1/5 * 2/3)

= 1/3 - (3/4 + 2/15)

= 1/3 - (3*15/4*15 + 2*4/15*4)

= 1/3 - (45/60 + 8/60)

= 1/3 - 53/60

= 1*20/3*20 - 53/60

= 20/60 - 53/60

= -33/60

= -11*3/20*3

= -11/20

D = 4/5 * (1/2 - 3/4 * 5/7)

= 4/5 * (1/2 - 15/28)

= 4/5 * (1*14/2*14 - 15/28)

= 4/5 * (14/28 - 15/28)

= 4/5 * -1/28

= -4/140

= -1*4/35*4

= -1/35

Réponse :

Bonsoir,

Explications étape par étape :

A = 5/3 + 4/5 x 1/3 = 5/3 + 4/15 = 25/15 + 4/15 = 29/15 ≈ 1,933

B = 7/5 x 4/3 - 1/7 x 3/5 = 28/15 - 3/35 = 196/105 - 9/105 = 187/105 ≈ 1.78

C = 1/3 - (3/4 + 1/5 x 2/3) = 1/3 - (3/4 + 2/15) = 1/3 - (45/60 + 8/60) = 1/3 - 54/60 = 20/60 - 54/60 = -34/60 ≈ -0.56

D = 4/5 x (1/2 - 3/4 x 5/7) = 4/5 x (1/2 - 15/28) = 4/5 x (14/28 - 15/28) = 4/5 x (-1/28) = - 4/140 ≈ -0.007

Bonne soirée