-3y + z = 7
2x + y + 2z = 11
x + z = 6
−3y + z = 7
2x + y + 2z = 11
2x + y + 2z = 11
x + z = 6
x −3y + 2z = 13
Add
Multiply
−3y + z = 7
2x + y + 2z = 11
x + z = 6
2
x
2
z
=
12
+
(x2)