$*6\mathrm{.}3$ Consider the function $f\frac{?}{b}=ar\frac{(w{)}_1}{b}ar(w{)}_3+\frac{w_2}{b}ar(w{)}_3\frac{+}{b}ar(w{)}_1{w}_2.$ Use the truth table to derive a circuit for $f$ that uses a $2-$to$-1$ multiplexer.

$6\mathrm{.}4$ Repeat problem $6\mathrm{.}3$ for the function $f\frac{?}{b}=ar\frac{(w{)}_2}{b}ar(w{)}_3+w_1{w}_2.$