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-x+2y+z=-3 x-4y+2z=-7 -3x+2y-2z=4

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higareda | Student, Grade 9 | eNoter

Posted July 12, 2013 at 7:04 PM via web

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-x+2y+z=-3

x-4y+2z=-7

-3x+2y-2z=4

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jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted July 12, 2013 at 7:46 PM (Answer #1)

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`-x+2y+z=-3 ----(1)`

`x-4y+2z=-7 ---(2)`

`-3x+2y-2z= 4 -----(3)`

 

`(2)+(3)`

`x-4y+2z-3x+2y-2z = -7+4`

`-2x-2y = -3 ----(4)`

 

`(1)xx2-(2)`

`2(-x+2y+z)-(x-4y+2z) = 2xx(-3)+7`

`-3x+8y = 1 ----(5)`

 

`(4)xx4+(5)`

`-11x = -11`

`x = 1`

 

From (4) we get` y = 1/2`

From (1) we get `z = -3.`

 

So the answers are x = 1,y = 1/2 and z = -3

 

 

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