We did a little work on the whiteboard to try to figure out how to deal with this case. They game me numbers, we worked out x - y and y - x. We talked about what was the same and what was different and then I asked how I could get the value of x - y given the value of y - x.
Of course multiplying by -1 will change the value, so how can we overcome that? Multiply by -1 again! Yeah, I lost a whole lot of them at this point. I know I did. I decided to let it sit with them for now and come back to it next week for a second try...
But then (I am so cruel) I made them factor by grouping. This is all leading somewhere, I told them. I'm not sure they believe me!
I think they were all really thankful to move on to "playing" with the tiles. We expanded, we factored; all was good again. I emphasized that they need to make a rectangle and that the x^2 tiles will be in one corner, while the unit tiles will be in the opposite corner.
A couple of examples for them to try:
Then we added negatives to the mix. Here is the link to the Gizmos activity. I click on "new" until I get a trinomial with negatives. I find this quicker for introducing the concept of adding zero pairs. And then they tried a few that were not monic.
Here is today's homework.