Question 1113326
You did not say what method you need.


If you add corresponding members of first and second equation, you eliminate y.  Now you will have two linear equations in the unknowns x and z...  Good for very simple Elimination Method to finish.


{{{system(2x-7z=2,x+2z=1)}}}


{{{system(2x-7z=2,2x+4z=2)}}}
Subtract one of them from the other...