Which of the equations shown have no solution?


1) 3x - 1 = 3x + 1

2) 2x - 1 = 1 - 2x

3) 3x - 2 = 2x - 3

4) 3(x-1) = 3x - 2

5) 2x + 2 = 2(x + 1)

6) 3(2x-1) = 2(3x - 1)