Use the rules of Boolean algebra to reduce these expressions to the simplest possible:

$(1)$ A$*$B$*$C $+$ A$*$B $+$ A$*$B$*$C$$

$(2)$ X$*$Y$*$Z $+$ X$*$Z

$(3)(+)$

$(+)$

$(4)$ X$*$Y $+$ X$*($W$*$Z $+$ W$*$Z$)$

$(5)($B$*$C$+$ A$*$D$)*($A$*$B$+$ C$*$D$)$

$(6)($X $+$ Y$+$ Z$)*($X$+$ Z$)$