To use algebra tiles you multiply the top row by the side row to expand. The squares symbolize x squared, the long strips signify x and the tiny squares signify the constant. Anything but red is positive making all the red tiles negative.

In the first photo, we start with (2x+2)(x-2), then you line up the corresponding tiles in the center, it should match up in alignment perfectly, and that’s how you know you’ve done it right.

Going backward is the same thing, just making sure it lines up and paying attention to the negative and positive signs. Here we started with 2x squared-6x+4 and then we worked backward making it all match up then verifying it, as you can see in the photo.