You have two lenses at your disposal, one with a focal length f$1=38\mathrm{.}5$ cm$,$ the other with a focal length f$2=-38\mathrm{.}5$ cm$.$ If you want to produce an image of the bulb that is enlarged by a factor of $2\mathrm{.}25,$ how far from the wall should the lens be placed? Also what unit is the answer in$?$