$(5$ marks$)$ Give the decimal value of the following numbers$).$ Show your work.

$($a$)$ The $2$s complement number $01010101$

$($b$)$ The $2$s complement number $10101101$

$($c$)$ The $2$s complement number $01111111$

$($d$)$ The $2$s complement number $10000111$

$($e$)$ The a sign$/$magnitude number $10001101$