SOLUTION: x+4y-z=7 x+y+z=2 -2x-2y+2z=-8 convert the system of equations into a matrix equation

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Question 519029: x+4y-z=7
x+y+z=2
-2x-2y+2z=-8

convert the system of equations into a matrix equation
Answer by Edwin McCravy(20059) About Me  (Show Source):
You can put this solution on YOUR website!
This system

system%28x%2B4y-z=7%2C%0D%0Ax%2By%2Bz=2%2C%0D%0A-2x-2y%2B2z=-8%29

becomes



You didn't say to solve it, but I will anyway, because no doubt
you'll be given some later to solve, and you can use this as a
model to go by:

To solve it find the inverse of the coefficient matrix, which is



Then left-multiply both sides of the matrix equation by this inverse:



Multiply the first two matrices on the left, and multiply the
matrices on the right:



Multiplying the matrices on the left (the one on the left is the identity
matrix)

%28matrix%283%2C1%2Cx%2Cy%2Cz%29%29=%28matrix%283%2C1%2C2%2C1%2C-1%29%29

So the solution is x=2, y=1, z=-1.

Edwin