Hi I'm stuck in this problem again. :(

Can somebody please help me? Thank you.

Using Gaussian elimination with back-substition or Gauss-Jordan Elimination solve the following problem.

A small corporation borrowed $500,000 to expand its product line. Some of the money was borrowed at 9%, some at 10%, and some at 12%. How much was borrowed at each rate if the annual interest was $52,000 and the amount borrowed at 10% was 2.5 times the amount borrowed at 9%?