Bonjour

A = 8/5 + 2/5 x 1/2

A = 8/5 + 2/10

A = (8 x 2) / (5 x 2) + 2/10

A = 16/10 + 2/10

A = 18/10

A = (2 x 9) / (2 x 5)

A = 9/5

B = 1/2 - 6/10 x 3/2 - 1/7

B = 1/2 - 18/20 - 1/7

B = (1 x 70) / (2 x 70) - (18 x 7) / (20 x 7) - (1 x 20) / (7 x 20)

B = 70/140 - 126/140 - 20/140

B = - 76/140

B = (4 x - 19) / (4 x 35)

B = - 19/35.

C = 3/5 x 2/5 + 7/10

C = 6/25 + 7/10

C = (6 x 2) / (25 x 2) + (7 x 5) / (10 x 5)

C = 12/50 + 35/50

C = 47/50

D = 4/25 - (12/30 + 1/5)

D = 4/25 - [12/30 + (1 x 6) / (5 x 6)]

D = 4/25 - (12/30 + 6/30)

D = 4/25 - 18/30

D = (4 x 6) / (25 x 6) - (18 x 5) / (30 x 5)

D = 24/150 - 90/150

D = - 66/150

D = (6 x - 11) / (6 x 25)

D = - 11/25.

Réponse :

Explications étape par étape

Bonjour

Calculer

A = 8/5 + 2/5 x 1/2

A = 8/5 + 2/2 x 1/5

A = 8/5 + 1/5

B = 3/5 x 2/5 + 7/10

B = 6/25 + (7 x 5)/(10 x 5)

B = (6 x 2)/(25 x 2) + 35/50

B = 12/50 + 35/50

C = 1/2 - 6/10 x 3/2 - 1/7

C = 1/2 - (2 x 3)/(2 x 5) x 3/2 - 1/7

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

C = 1/2 - 9/10 - 1/7

C = (1 x 35)/(2 x 35) - (9 x 7)/(10 x 7) - (1 x 10)/(7 x 10)

C = 35/70 - 63/70 - 10/70

C = 35/70 - 73/70

C = 38/70

C = (2 x 19)/(2 x 35)

C = 19/35

D = 4/25 - (12/30 + 1/5)

D = 4/25 - (6 x 2)/(6 x 5) - 1/5

D = 4/25 - 2/5 - (1 x 5)/(5 x 5)

D = 4/25 - 10/25 - 5/25

D = 4/25 - 15/25

D = -11/25