Question 265445
7x+5y+z=0    ------------ 1
-x+3y+2z=16  ------------ 2
x-6y-z=-18   ------------ 3

adding Eq.s 1 & 3

we get 8x-y=-18 --- 4

multiply eq.3 by 2 and add to eq.2

we get x-9y=-20 --- 5 

multiply eq.5 by 8 and subtract it from eq.4

we get 71y=142

so y=2

from eq. 5    x-18=-20

so x=-2

from eq.1  -14+10+z=0

so z=4

  x=-2, y=2, z=4