Create an eight$-$by$-$one multiplexer using some of the $2-$by $1$ multiplexers. $2)$ Implement the function f $($w$,$ x$,$ y$,$ z$)=$m$(0,1,5,7,8,10,13,14,15)$ a$.$ Using two $8-$way multiplexers with an active low enable, plus an OR gate b$.$ Using one $8-$way multiplexer $3)$ Implement the following functions using a ROM a$.$ X$($A$,$ B$,$ C$,$ D$)=$m$(1,3,5,7,8,9,11)$ b$.$ Y$($A$,$ B$,$ C$,$ D$)=$m$(0,2,4,5,7,8,10,11,12)$ c$.$ Z$($A$,$ B$,$ C$,$ D$)=$m$(1,2,3,5,7,10,12,13,14,15)$