Bonsoir j'ai besoin d'aide pouvez vous m'aidez svp Calcule les expressions suivantes pour x = 2/3 A= x + 2 B = 2x - 3 C = 4(1-x) D= x au carré - 4x + 1

Bonsoir,

Calcule les expressions suivantes pour x = 2/3

A= x + 2  

A = 2/3 + 2

A = 2/3 + (2 x 3) / (1 x 3)

A = 2/3 + 6/3

A = 8/3

B = 2x - 3

B = 2 * 2/3 - 3

B = 4/3 - (3 x 3) / (1 x 3)

B = 4/3 - 9/3

B = - 5/3

C = 4(1-x)

C = 4 (1 - 2/3)

C = 4 [(1 x 3) / (1 x 3) - 2/3]

C = 4 (3/3 - 2/3)

C = 4 * 1/3

C = 4/3

D= x² - 4x + 1

D = 2/3² - 4 * 2/3 + 1

D = 2²/3² - 8/3 + 1

D = 4/9 - (8 x 3) / (3 x 3) + (1 x 9) / (1 x 9)

D = 4/9 - 24/9 + 9/9

D = - 11/9

Hello !

On remplace dans chaque expression x par 2/3

A = x+2

A = 2/3 + 2 = 2/3 + 6/3 = (2+6)/3 = 8/3

B = 2x-3

B = 2(2/3)-3 = 4/3 - 3 = 4/3 - 9/3 = -5/3

C = 4(1-(2/3))

C = 4×(1/3) = 4/3

D = x²-4x+1

D = (2/3)² - 4(2/3) + 1 = 4/9 - 8/3 + 1 = 4/9 - 24/9 + 9/9

D = (4+9-24)/9 = -11/9

Bonne soirée