Which line shows the first error in the solution?

(1). 4x+8=2x-10

(2). 4x-2x+8=2x-2x-10

(3). 2x+8=-10

(4). 2x+8-8=-10-8

(5). 6x=-2

(6). 6x/6=-2/6

(7). x=-1/3