SOLUTION: solve the system x-y+z=-4 x+2y-z=-2 x+y-4z=1

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Question 328163: solve the system
x-y+z=-4
x+2y-z=-2
x+y-4z=1
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.x-y%2Bz=-4
2.x%2B2y-z=-2
3.x%2By-4z=1
Subtract eq. 1 from eq. 2,
x%2B2y-z-x%2By-z=-2-%28-4%29
4.3y-2z=2
Subtract eq. 1 from eq. 3,
x%2By-4z-x%2By-z=1-%28-4%29
5.2y-5z=5
Mutliply eq. 4 by 2 and eq. 5 by -3 to eliminate y,
6y-4z-6y%2B15z=4-15
11z=-11
highlight%28+z=-1%29
Then use either eq.4 or eq. 5 to solve for y.
3y%2B2=2
3y=0
highlight%28+y=0%29
Finally use 1,2,3 to solve for x.
x%2B0%2B%28-1%29=-4
highlight%28+x=-3%29