1. The problem statement, all variables and given/known data Solve for a, b, and c. 4c+6b+14a=25 6c+14b+36a=21 14c+36b+98a=105 2. Relevant equations 3. The attempt at a solution I need to solve this without using matrices. The easiest way would be to get it into row echelon form and back-substitute. However, I'm not sure how you can get this system of equations into row echelon form. I can subtract 6 times the first equation from the third equation: 14c+36b+48a=105 - 24c+36b+84a=150 ------------------------ -10c+0b+14a=-45 so you get: -10c+0b+14a=-45 6c+14b+36a=21 14c+36b+98a=105 Next the only thing you could do would be subtract 7 times the first equation from the third equation, but if you did that you would be getting rid of the a term but reintroducing the b term which I just eliminated. How do you get this into Row Echelon form to solve?