SOLUTION: how do you solve the system of equations with these three equations? x-y+z=8 x+y+z=6 x+y-z=-12

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Question 365371: how do you solve the system of equations with these three equations?
x-y+z=8
x+y+z=6
x+y-z=-12
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.x-y%2Bz=8
2.x%2By%2Bz=6
3.x%2By-z=-12
Add eq. 1 and eq. 3,
x-y%2Bz%2Bx%2By-z=8-12
2x=-4
highlight%28x=-2%29
.
.
.
Add eq. 1 and eq. 2,
x-y%2Bz%2Bx%2By%2Bz=8%2B6
2x%2B2z=14
2%28-2%29%2B2z=14
2z=18
highlight%28z=9%29
.
.
.
Then from eq. 2,
x%2By%2Bz=6
-2%2By%2B9=6
highlight%28y=-1%29