Exercice 1* Résoudre les équations suivantes : a. 3x + 1 = 5x - 1 b. 2(x + 1) - 3(x – 7) = 1 C. 3(x - 4) = 4(x + 4) d. 5[2(3 – x) — 2]= 5x +1 Svp !?

Bonjour,

Sauf erreur d'énoncé :

a) 3x + 1 = 5x ⇔ 5x - 3x = 1 ⇔ 2x = 1 ⇔ x = 1/2

b) 2(x + 1) - 3(x – 7) = 1

⇔ 2x + 2 - 3x + 21 = 1

⇔ - x + 23 = 1

⇔ x = 23 - 1

⇔ x = 22

c) 3(x - 4) = 4(x + 4)

⇔ 3x - 12 = 4x + 16

⇔ 4x - 3x = - 12 - 16

⇔ x = - 28

d) 5[2(3 – x) - 2]= 5x + 1

⇔5[6 - 2x - 2] = 5x + 1

⇔5(-2x + 4) = 5x + 1

⇔-10x + 20 = 5x + 1

⇔5x + 10x = 20 - 1

⇔15x = 19

⇔x = 19/5