How/Can I use one direct tv box for 2 TVs?

I was supposed to get another box/line installed in extra room for free since it was only a few days after initial installation. They want to charge me $200 now! The box I have now is in the master bedroom, which is next to the guest (roommate's) room I wanted a new box in. Could I just switch the wires to connect the TV for my room mate when I'm not using it in the master? I hardly use it. How would this work? Could I get a splitter and just leave it plugged into both? Im electronically illiterate so go easy on the technical terms lol. Thanks!!