Respuesta :

[tex]6+2x=x-6[/tex]
[tex]2x-x=-6-6[/tex]
[tex]x=-12[/tex]

The anwers is - the last equation, because having solved it, it is the same value :
[tex]2x=x-12[/tex]
[tex]2x-x=-12[/tex]
x=-12

I hope I was of help ;)
Dannymal
6 + 2x = x - 6
2x = x - 6 - 6
2x = x - 12
2x - x = -12
x = -12

SIMPLER WAY
6 + 2x = x - 6
Subtract 6 from both sides;
2x = x - 12
2x - x = -12
x = -12

CHECK

6 + - 24 = -12 - 6
-18 = 18!

Therefore if you see one of my workouts it has 2x - x = 12 so the one at the very right (2x - x = 12) is the answer :)