Bonjour,

b) 3x + 1 = 2x - 5 - x + 1

      4             8        2

6x + 2 = 2x - 5 - 4x + 4

    8           8           8

6x + 2 = 2x - 5 - 4x + 4

6x - 2x + 4x = - 5 + 4 - 2

8x = - 3

x = - 3/8

c) 5x + 1 - (x - 4) + 3 = 4 (x + 2)

5x + 1 - x + 4 + 3 = 4x + 8

5x - x - 4x = 8 - 1 - 4 - 3

0x = 0