Bonjour !

Exercice 4 :

=> 7x - 4 = 5x+6

7x - 5x = 6+4

2x = 10

x = 10/2

x = 5

=> 3 - 2x = - 2+3x

-2x - 3x = - 2-3

-5x = - 5

x = 5/5 = 1

=> 3x-2x+8 = 5+4-8x

3x-2x+8x = 5+4-8

9x = 1

x = 1/9

Bon courage.