Use matrices to solve the system of equations (if possible). Use Gaussian elimination with back-substitution. (If not possible, enter IMPOSSIBLE. If the system is dependent, express x and y in terms...

Extracted text: Use matrices to solve the system of equations (if possible). Use Gaussian elimination with back-substitution. (If not possible, enter IMPOSSIBLE. If the system is dependent, express x and y in terms of the parameter a.) 3x - 2y = -30 x + 3y= 23 (x, y)