would 2-x/2 just be -x?
no,
If you mean 2 - x/2 as you wrote it, then that's it, 2 - x/2
If you meant (2-x)/2, it would be just that, or 1 - x/2
If you mean 2 - x/2 as you wrote it, then that's it, 2 - x/2
If you meant (2-x)/2, it would be just that, or 1 - x/2