12. -/1 points LarLinAlg8 3.R.041 My Notes Use the determinant of the coefficient matrix to determine whether the system of linear equations has a unique solution. x1 2x2 6x3- 1 7x15x2 15x3-4 5x1 + x2 + 3x3 =-8 O The system has a unique solution because the determinant of the coefficient matrix is nonzero. O The system has a unique solution because the determinant of the coefficient matrix is zero. The system does not have a unique solution because the determinant of the coefficient matrix is nonzero O The system does not have a unique solution because the determinant of the coefficient matrix is zero. 13. -/1 points LarLinAlg8 3.R.065. My Notes Use a software program or a graphing utility and Cramer's Rule to solve (if possible) the system of linear equations. (If not possible, enter IMPOSSIBLE.) 0.2x1-0.6x2 = 3.8 -x1 + 1.4x2 =-12.6 (x1, x2)