Step 1 :Represent the system of equations in matrix form.
Step 2 :Use Gaussian elimination to reduce the system to its row echelon form.
Step 3 :If the system has a unique solution, the row echelon form will have a leading 1 in each row. If the system has no solution or infinite solutions, the row echelon form will have a row of zeros.
Step 4 :The matrix representation of the system is: \[ A = \begin{bmatrix} 6 & -1 & 3 \\ 1 & 3 & -1 \\ 3 & 3 & -4 \end{bmatrix}, b = \begin{bmatrix} 9 \\ -5 \\ 5 \end{bmatrix} \]
Step 5 :Solving the system gives the solution: \[ x = \begin{bmatrix} 2 \\ -3 \\ -2 \end{bmatrix} \]
Step 6 :Therefore, the system has a unique solution and it is (2, -3, -2).
Step 7 :Final Answer: \(\boxed{\{(2, -3, -2)\}}\)