$,($x$)/(2)+($x$^(2))/(4)-($x$^(3))/(8)+($x$^(4))/(16)+($x$^(5))/(32)-($x$^(6))/(64)+$cdots$(($x$)/(2))^(3$k$),(($x$)/(2))^(3$k$-1),$ and $\{$:$(($x$)/(2))^(3$k$-2).)$ In the following exercises, express the sum of each power series in terms of geometric series, and then express the sum as a rational function.