Gauss-Jordan equation I am stuck on

I've never been any good at math, but I seem to be getting nowhere with this problem (Headbang)

4x + 4y + z - 6w = 0

-5x - y - 5z + 3w = 0

7x + 11y - 2z - 15w = 0

E-mailed the prof for help, told me this:

It is not a 'trick question', it is just one that you will have

infinitely many solutions (it cannot have just one, it does not have enough

equations, it cannot have no solution, because all the equations are set to

zero, so if all the variables are set to zero then the equations are

satisfied). It will have some almost nasty looking fractions in it (I

think). Don't let fractions scare you.

Any help is appreciated. Thanks so much.