I went to the video and saw the problem you spoke of. It's actually (1/2) x - 4 = -2 - (5/2)x
I would have encouraged you to first collect all of the x's to one side. So I would have taught you to add (5/2) x to both sides, thereby changing the equation to (6/2) x - 4 = -2
Simplify to 3x - 4 = -2
THEN add 4 to both sides since you want to get x alone.
3x = 2
Divide by three, giving x = 2/3