text: solve this problem? i have a 15yr $115.000 mortgage at 7.1% what is the principle after $1040.09 1st payment? i have a 15 year $115,000 mortgage at 7.1%.  my monthly payment is $1040.09.  find the principle after the first payment. $114,640.32   $359.68 was paid towards your principal  $680.41 was paid towards your interest