Bonjour,

J'en fais quelques unes de la dernière colonne pour te montrer la méthode :

x + 7 = 2x + 4

7 - 4 = 2x - x

x = 3

x - 1 = - 8x + 1

x + 8x = 1 + 1

9x = 2

x = 2/9

2x + 4 = 4x - 5

4 + 5 = 4x - 2x

9 = 2x

x = 9/2 = 4,5

3x - 9 = 2 + 9x

-9 - 2 = 9x - 3x

-11 = 6x

x = -11/6

9x + 12 = 9 - 4x

9x + 4x = 9 - 12

13x = - 3

x = -3/13

-x + 4 = 6 + 2x

4 - 6 = 2x + x

-2 = 3x

x = -2/3

-6x + 2 = 9 - 3x

2 - 9 = -3x + 6x

3x = -7

x = -7/3

-5x - 15 = -3x + 4

-15 - 4 = -3x + 5x

2x = -19

x = -19/2 = -9,5

=> Maintenant que tu as compris la méthode à toi de continuer, si tu as des questions n'hésite pas