Question 313929
2x - y + 3z = 1
-x +2y - z =-2
x + y + 2z = -1 
:
No
Multiply the last equation by -1 and add and see what happens
2x - y + 3z = 1
-x +2y - z = -2
-x - y - 2z = 1
--------------------adding eliminates all three variables