Question 231441
You can either solve the system by back substitution or elimination.  I chose to solve it by substitution.  

So we solve the first equation for x and get x = -2+3z.  Now we can substitute that into the other equations.  I'll leave the algebra for you to do but you will end up with:

y+7z=11
2y+7z=8

And now we can solve the system of 2 equations and 2 unknowns.  Again I chose to do this by substitution but elimination would work as well.  I solved the top equation for y and got y=11-7z. Then plugged that into the bottom equation so I could solve for z.  Again I'll leave the algebra for you to do but you should get z = 2.  Then you substitute that into your equation for y and end up with y = -3.  Then the value in for z into the equation for x and you will see that x = 4. 

So your final solution is (4,-3,2).