Subscript notation is frequently used for working with larger systems of equations. Use a matrix approach to solve the system. Express the solutions as 4-tuples of the form (x1, x2, x3, x4). x1 − 3x2 − 2x3 + x4 = −6 −2x1 + 7x2 + x3 − 2x4 = −1 3x1 − 7x2 − 3x3 + 3x4 = −8 5x1 + x2 + 4x3 − 2x4 = 24 (x1, x2, x3, x4) =