2.1 speakers coming out of stereo receiver?

I have 2 cabinets I have made for my 1982 teledyne speakers and they sound amazing. great highs and decent bass for having 35 watts each.. But not enough for me. I just recently bought a dayton 70 watt woofer that goes down to 25 hz up to 2500 hz-(the 10 inch classic). I have pretty much no money because I am 14. Not enough to spare for a 2.1 receiver.. I do have a philips mini hifi stereo 300 watt amplifier and receiver that my tv or pc can be attached to one at a time via rca wires... Now what I am wondering is if I can use the woofer and the 2 teledynes at the same time...if so, please, please tell me how!! I have been waiting for this moment for a while now... no money for a new receiver and I have this stereo receiver at hand... thanks for reading!!