$11\mathrm{.}26.$ Find the bilateral z$-$transforms and the regions of convergence for the following functions:

$($a$)0\mathrm{.}7$nu$[$n$]$

$($b$)0\mathrm{.}7$nu$[$n $-7]$

$($c$)0\mathrm{.}7$nu$[$n $+7]($d$)-0\mathrm{.}7$nu$[-$n $-1]$