Monday, June 22, 2015

`2x + 2y - z = 2, x - 3y + z = -28, -x + y = 14.` Use matricies to solve the system of equations (if possible). Use Gauss-Jordan elimination.

`2x+2y-z=2`


`x-3y+z=-28`


`-x+y=14`


The equations can be written as,


`[[2,2,-1,|2],[1,-3,1, |-28],[-1,1,0,|14]]`


R2`->` R1+R2+R3


`[[2,2,-1,|2],[2,0,0,|-12],[-1,1,0,|14]]`


R1 `->` R1-R2


`[[0,2,-1,|14],[2,0,0,|-12],[-1,1,0,|14]]`


R3 `->` 2R3+R2


`[[0,2,-1,|14],[2,0,0,|-12],[0,2,0,|16]]`


R1`->` R1-R3


`[[0,0,-1,|-2],[2,0,0,|-12],[0,2,0,|16]]`


Now,


`-z=-2`


`:.z=2` 


`2x=-12`


`x=-12/2=-6`


`2y=16`


`y=16/2=8`


So, the solutions are x=-6,y=8,z=2

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