The last one disappearing suggests you have infinitely many solutions.
Supposing your variables to be x, y, and z, you seem to have:
x = -2z
y = z
Pick any z you like and calcualte its related x and y.
I've got an augmented matrix in row reduce form but I'm not sure what the solution is for the variables. If some one could describe what the answer is and why, I would greatly appreciate it. Thanks! Ultros
( 1 0 2 0 )
( 0 1-1 0 )
( 0 0 0 0 )