j'ai besoins d'aide svp A= 2/7-3/7×14/9 B=-7/8×(2/3-1) C= 4/5×1/4+2/5​

Bonjour

A= 2/7-3/7×14/9

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×(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= 4/5×1/4+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)

C = 3/5.

Réponse :

Explications étape par étape

Bonjour

A= 2/7-3/7×14/9

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

A = 2/7 - (7 x 2)/7 x 3/(3 x 3)

A = 2/7 - 2 x 1/3

A = (2 x 3)/(7 x 3) - (2 x 7)/(3 x 7)

A = 6/21 - 14/21

A = (-8/21)

B=-7/8×(2/3-1)

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

B = -7/8 x (-1/3)

B = 7/(8 x 3)

B = 7/24

C= 4/5×1/4+2/5​

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

C = 1/5 + 2/5

C = 3/5