need advice on cable wire

I have to move my projector hdtv across the room..but the cable will
not reach that area. I found a white 20' footer of RG59/u I believe
its called. Could i hook that up with the existing cable and a
connector? Also, I may need to use a splitter..would any splitter do?
I have another hdtv in bedroom upstairs from the projector tv and
would like to get hd up there.

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