Solution no. 2: Response to Eng'g Economics problem (Lump Sum calculation) submitted by a subscriber

This is the video of my solution to @marsthinie sarsalejo's 2nd engineering economics question she made in a comment.
Mr. Ramirez borrowed P15,000 two years ago. The terms of the loan are 10% interest for 10 years with uniform payments. He just made his second annual payment. How much principal does he still owe?