Answer
$\emptyset$.
Work Step by Step
1. Reduce the first equation (divide by 3) to get $x+2z=-1$
2. Reduce the third equation (divide by 2) to get $x+2z=-\frac{1}{2}$
3. Take the difference between the two equations above, we have $0=\frac{1}{2}$, which is not possible.
4. Thus the solution set is $\emptyset$.
