In this case I'd usually use a three way at the top. The 3.5 leg on the first three way will go to a four way. The first 7 leg would go to the cable modem, and the second 7 leg would go to any TV.
The 3.5 and 7 leg can be swapped if the cable modem doesn't like it, but your TVs might be getting a little fuzzy at this point.