Question

Question #9a21e

Answer 1

`x=2, y=-1, z=1`

Explanation:

let `x+2y-4z = -4` be equation 1
let `2x+5y-9z =-10` be eq. 2
let `3x-2y+3z = 11` be eq.3

eq.1 x 2
`2x+4y-8z = -8` (eq.4)

eq.2 - eq.4
`y-z=-2` (eq.5)

eq.1 x 3
`3x+6y-12z=-12` (eq.6)

eq.6-eq3
`8y-15z=-23` (eq.7)

eq.5 x 8
`8y-8z=-16` (eq.8)

eq.7 - eq.8
`-7z=-7`
`:. z=1`

sub `z=1` into eq.5
`y-1=-2`
`:. y=-1`

sub `z=1 and y=-1` into eq.1
`x-2-4=-4`
`:. x=2`