Question

(9-1/z^2)/(3-1/z)

Answer 1

let 1/z =t so than your equation will be

(9-t^2)/(3-t) =(

so (9-t^2) you see that this is a difference of twoo squares and what you know that can writing after this formula in the form of (...
...after this you will get what and how will can simplifie and hence will get the right answer sure

Answer 2

but finaly you dont forget replace in place of t the 1/z

good luck

bye