Use the Gauss–Jordan method to solve the following system of linear equations:

(A system with more variable than equations is calledunderdetermined.)

x+ y − z + 2w = −20

2x − y + z + w = 11

3x − 2y + z − 2w = 27

So putting this into matrices, I get

[1 1 -1 2 | -20]

[2 -1 1 1 | 11 ]

[3 -2 1 -2 | 27]

^ note, that's all supposed to be in one matrix

I've tried over and over again, but I just can't get this system into row-reduced form...can someone please help?