Algebra tiles for expresions with one or two variables (1-tile, x-tile, y-tile, xx-tile, yy-tile, xy-tile)

For use in classroom see for example 

The gcodes are for two-colored sets (prepared for my MK3S+).
Classical one is for one variable, expanded for two variables.
Feel free to mix your optimal set.

There is a + and - sign so use of one color is also possible (but not optimal). Names of variables are not there, as I find it limiting (kids should be able to use different variables and sometimes a tile can mean whole expression in itself).