Hello everyone. I Need some help to figure out how they manage to solve this inverse Z-transform. Its a little bit more steps in the solution but the final step that im wondering about is shown in the following attachment. (Im new to this site and also to the inline-latex-functionallity, so ive used openoffice+gimp instead, hope its ok). Its clear that the inverse z-transform of the second term is a^|k|, but dont you need to perform the multiplication of the two terms before you perform inverse transform? and if you do, you end up with four parts to inverse-transform wich only the first one is a "clean" a^|k| and the rest of the parts will include the b-variable... wich i dont see how you just can skip while performing inverse transform and then just add after your done. :\.. I guess what im asking is if someone could explain in a simple manner a few steps in between.. so I could understand how they have found the solution. Thanks!