Consider the following systems.

Determine the stability.

Determine the causality. If the system is not causal, find the non$-$causal term in the impulse response $h[n].$ Hint: long division and get terms $z,z^2,z^3$dots.

$($a$)H(z)=\frac{3(z+0\mathrm{.}8)}{z(z-0\mathrm{.}8)(z-2)}$

$($b$)H(z)=\frac{3(z-1{)}^2}{z^3-1\mathrm{.}6z^2+0\mathrm{.}64z}$

$($c$)H(z)=\frac{z^3+z^2+1}{(z-1)(z-2)}$