If we use the same procedure as we did in HW2D then we will find out it is not time variant. We get
$ \,\ y(t)= (k + 1)^2 \delta[n - n_0 -(k + 1)] $
$ \,\ z(t) = (k + 1 + n_0)^2 \delta[n - n_0 -(k + 1)] $
