Question 12967
Ok, you have:

{{{-2(z-4)-(3z-2) = -2-(6z-2)}}}  You did the left side just fine.  But on the right side, the -2 is not multiplying the (6z-2), at least, going by the way you have written it. So your second step is in error. It should be:

{{{-2z+8-3z+2 = -2-6z+2}}} Collect like-terms.
{{{-5z+10 = -6z}}} Add 6z to both sides.
{{{z+10 = 0}}} Subtract 10 from both sides.
{{{z = -10}}}