bonjour, pourriez-vous m'aider s'il vous plait en mathématiques merci calculer en simplifiant 1) A= 2/7-3/7*14/9 B = -7/8*(2/3-1) C = 4/5*1/4+2/5 2)a. 3/5/1/5 b

Bonjour,

Calculer en simplifiant  :

1) A= 2/7-3/7*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*(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

2)

a. 3/5 : 1/5  

= 3/5 x 5

= 15/5

= (5 x 3) / (5 x 1)

= 3

b.22/7 :-11

= 22/7 x - 1/11

= - 22/77

= (11 x - 2) / (11 x 7)

= - 2/7