Find the $\mathcal Z$-transform of this function?
Doing some calculations is appreciated. However, it is preferred that you write them in the question because a picture can vanish more easily. Do not hesitate to edit the math.

To help you with an hint in checking your answer, remember that:

$$ a^{-n} = \left(\frac{1}{a}\right)^n$$

a standard trick to play with known tables.