4:43 a webassign.net 4. [-/1 Points] DETAILS ROLFFM8 2.2.018. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Determine the matrix of coefficients and the augmented matrix for the system of linear equations. X1 - 3X2 + X3 + 4X4 = 4 6X1 - X2 - X3 - X4 = 9 X1 + 7X2 =9 X1 + X2 + X3+ X4 = 1 1 -3 1 4 X1 -3X2 X3 4X4 4 6 -1 -1 -1 5X1 -X3 -X4 9 O coefficient matrix: 7 0 augmented matrix: -X2