Réponse :

1)

5x + 2 = 2x + 6

5x + 2 - 2 = 2x + 6 - 2

5x = 2x + 4

5x - 2x = 4

3x = 4

x = 4/3

2)

2(3x + 3) = -2(x - 7)

6x + 6 = -2x + 14 (distribution)

6x + 6 - 6 = -2x + 14 - 6

6x = -2x + 8

6x/-2 = -2x/-2 + 8

-3x = x + 8

-3x - 8 = x

x - 8 = x + 3

x - 8 + 8 = x + 3 + 8

x = x + 11

x - x = 11

-x/-1 = 11/-1

x = -11