Using the properties of Boolean algebra, simplify the expressions: i$)xy\text{'}+yz+z\text{'}w+x\text{'}y\text{'}z$

ii$)x(y+xy\text{'})(z+yx\text{'})(z+y\text{'}w)+x\text{'}(y+zw\text{'})$ iii$)$ xyz$\text{'}$w$\text{'}+$y$\text{'}$x$+$x$\text{'}$w$\text{'}($z$+$w$\text{'}$y$)$