Stereo 3-way bookshelf speakers + subwoofer?

I recently purchased two 3-way bookshelf speakers and a 10 in subwoofer (inside enclosure) from the thrift store. The subwoofer has a speaker wire in (L/R Pos/Neg), i assume that is for an amplifier, and speaker wire out (L/R Pos/Neg), I assume for two sattelites. Could I attach my two 3-way bookshelf speakers to the subwoofer outputs and have it work properly? (btw, the bookshelf speakers are 6ohms, and the sub is 8ohms).