How to z-transform these equations into matlab using symbolic math toolbox?

How to input the equations and perform z-transform using the symbolic math toolbox?

Answer 1

[Walter Roberson]

syms n z
ztrans( (1/sym(3))^n*dirac(n-2)+(sym(9)/10)^(n-3)*dirac(n), n, z)

Unfortunately there appears to be a weakness in not knowing that the ztrans of dirac(n) is 1 .

Generally speaking it seems to be weak on many of the items listed in https://en.wikipedia.org/wiki/Z-transform#Table_of_common_Z-transform_pairs