I also tried to model for , but it is impossible to show 3 dimensions with algebra tiles, unless I stacked 10 of the tiles. If I could model this I would need a cube with the side length of . The answer would be
The difference in each of the equations is the negative sign or positive sign and the number of times they are multiplied together which produces slightly different answers.
Use Pascals Triangle to expand (x-1)^3 and correct your answer above.