67 Calculer en simplifiant si possible et vérifier avec la calculatrice a=2/7 - 3/7 x 14/9 b= -7/8 x (2/3 - 1) c= 4/5 x 1/4 + 2/5 Pouvez vous m’aidez svp

Bonjour,

a=2/7 - 3/7 x 14/9

a = 2/7 - 42/63

a = (2 x 9) / (7 x 9) - 42/63

a = 18/63 - 42/63

a = -24/63

a = (3 x - 8) / (3 x 21)

a = - 8/21.

b= -7/8 x (2/3 - 1)

b = - 7/8 x [2/3 - (1 x 3) / (1 x 3)]

b = - 7/8 x (2/3 - 3/3)

b = - 7/8 x - 1/3

b = 7/24

c= 4/5 x 1/4 + 2/5

c = 4/20 + (2 x 4) / (5 x 4)

c = 4/20 + 8/20

c = 12/20

c = (4 x 3) / (4 x 5)

x = 3/5.

Réponse :

Bonjour

Explications étape par étape

A = 2/7 -3/7 X 14/9

A = 2/7 - 42/63

A = 2/7 X 9/9 -42/63

A = 18/63 -42/63

A = -24/63

A = -8/21

B = -7/8 X (2/3 -1)

B = -7/8 X ( 2/3 -3/3)

B = -7/8 X -1/3

B = +7/24

C = 4/5 X 1/4 +2/5

C = 4/20 +2/5

C = 4/20 +2/5 X 4/4

C = 4/20 +8/20

C = 12/20 = 6/10 = 3/5