Express each Boolean expression E$($x$,$ y$,$ z$)$ as a sum$-$of$-$products and then in its complete sum$-$of$-$products

form: $($a$)$ E $=$ y$($x $+$ yz$)\text{'}=$ Blank $1$; $($b$)$ E $=$ x$($xy $+$ y$\text{'}+$ x$\text{'}$ y$)=$ xyz $+$ Blank $2+$ xy$\text{'}$z $+$ Blank