Answer
$\{(x,y,z)|y=\frac{9}{8}z+\frac{69}{8}, x=\frac{7}{4}z+\frac{39}{4} \}$ where $z$ is any real number.
Work Step by Step
1. Multiply the 2nd equation by -2 and add to the 1st to get $-8y+9z=-69$
2. Multiply the 2nd equation by -5 and add to the 3rd to get $-16y+18z=-138$ or $-8y+9z=-69$
3. We can see the above two equations are identical, thus the system is dependent with solutions $\{(x,y,z)|y=\frac{9}{8}z+\frac{69}{8}, x=\frac{7}{4}z+\frac{39}{4} \}$ where $z$ is any real number.
