Question $5$: Simplify the following Boolean expressions to a minimum number of literals:

$($a$)$ points$)$

ab$\text{'}+$ab

$($b$)$ points

$($w$+$x$\text{'})($w$+$x$)$

$($c$)$

$($s$\text{'}+$y$\text{'})*($s$+$w$)\text{'}$