A $-3\mathrm{.}0-$C point charge and a $-9\mathrm{.}0-$C point charge are initially extremely far apart. How much work does it take to bring the $-3\mathrm{.}0-$C charge to x $=3\mathrm{.}0$ mm$,$ yy $=0\mathrm{.}00$ mm and the $-9\mathrm{.}0-$C charge to xx $=-3\mathrm{.}0$ mm$,$ yy $=0\mathrm{.}00$ mm$?($kk $=1/4$$0$$0=8\mathrm{.}99109$ N $$ m$2/$C$2)$

$27$ J$6\mathrm{.}8$ J$40$ J$81$ J