Consider a discrete$-$time LTI system with impulse response

$1*$ h$[$n$]=$&$2)$ u$[$n$]$

determine the response to each of the following input signals:

$3$o$$n

$($a$)$ x$[$n$]=$c$$e$4$ u$[$n$]$

$1$o$$n

$($b$)$ x$[$n$]=($n$+1)$c$$e$4$ u$[$n$]$

$($c$)$ x$[$n$]=(-1)$n