Use the Gauss-Jordan method to solve each system of equations. For systems in two variables with infinitely many solutions, give the solution with y arbitrary. For systems in three variables with infinitely many solutions, give the solution with z arbitrary.

x + 3y - 2z - w = 9

4x + y + z + 2w = 2

-3x - y + z - w = -5

x - y - 3z - 2w = 2