So my kids still amaze me sometimes--I ask them to find another way of writing 2x+5x, and some say 5x+2x, while others say 6x+1x--all not what I intended, yet for them organic, and they use elaborate rearrangements--and stand by it all. It is a good way to end an otherwise rocky week, and the sort of thing which is relatively overlookable, but worth a lot more--students don't necessarily "buy" simplest terms.