how can i hook up my computer to a tv to use a monitor?

Yes, you should be able to do that. Many of the inexpensive TVs these days often have at least HDMI input, so you can buy a third-party Mini DisplayPort to HDMI Adapter and an HDMI cable. Connect the adapter to the MBP and the cable from the adapter to the TV. If necessary, switch the TV to the HDMI input. Select mirroring in System Preferences > Displays > Arrangement and pick a mutually acceptable resolution. That should be it.

That was the answer for a Thunderbolt port. (Thunderbolt ports can act as Mini DisplayPort ports; that is part of the definition of the Thunderbolt protocol as implemented on current Macs.)

I knew you have a Thunderbolt port because of your profile ("MacBook Pro (15-inch, Mid 2012)").

Here's one from Monoprice for less than $7. Just add an HDMI cable. I've had it for 8 months or so - works very well.

Clinton

There are many applicable adapters and adapter cables on Amazon, many more than the last time I looked.

One item that is new is an direct male-to-male Mini DisplayPort-to-HDMI cable. Originally the offerings were all Mini DisplayPort male to HDMI female, requiring a separate male-to-male HDMI cable as I described in my first post. Either way should work in principal if properly implemented.

I looked at one that used "Thunderbolt" in the item title. It said in the description that it also works with Mini DisplayPort also, as expected.

I cannot vouch for any specific adapters, though. (My MBP-R has an actual HDMI port, so I just use an HDMI cable.)

That is the adapter - just with a 10 foot cable: and it should work just fine.

Good luck,

Clinton