Answer
$\{(x,y,z)|x=5z-2, y=4z-3\}$
Work Step by Step
1. Add the 2nd and the 3rd equations to get $2x-10z=-4$ or $x-5z=-2$
2. Multiply 2 to the 1st equation, then add to the 2nd to get $x-5z=-2$
3. As the two equations above are identical, the system is dependent.
4. We have $x=5z-2$ and from the 1st eqn, we have $y=x-z-1=4z-3$
5. Solution $\{(x,y,z)|x=5z-2, y=4z-3\}$ where $z$ is any real number.