How much equity? Math problem.? (PLEASE answer!)?

For some reason am stuck on this math problem. Using the TI-83 plus, can someone show me how to work this problem?





Here is the problem:





%26quot;A home was purchased 12 years ago for $115,000. The home was financed by paying a 20% down payment and signing a 25 year mortgage at 7.0% compounded monthly on the unpaid balance. The market value is now $150,000. The owner wishes to sell the house. How much equity (to the nearest dollar) does the owner have in the house after making 144 payments?%26quot;





I know that the answer is: $83519





I just need to know the steps to take in order to work the problem and to come to the answer.





Thanks for any help.



I downloaded the virtual TI-83 plus to try to figure out your problem and all I come up with is... 3


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