2x+2y+2z=0
-2x+5y+2z=1
8x+y+4z=-1
Get rid of the -2x by adding the 1st equation to the 2nd equation:
2x+2y+2z=0
+7y+4z=1
8x+y+4z=-1
Get rid of the 8x by multiplying the 1st equation by -4 then
adding it to the 3rd equation:
-8x-8y-8z=0
+7y+4z=1
8x+y+4z=-1
-8x-8y-8z=0
+7y+4z=1
-7y-4z=-1
Then divide the 1st equation through by -8
x+ y+ z=0
+7y+4z=1
-7y-4z=-1
Get rid of the -7y by adding the 2nd equation to the 3rd equation
x+ y+ z=0
+7y+4z=1
The whole 3rd equation vanished when I did that.
Solve the second equation for y
7y+4z=1
7y=1-4z
y=
Substitute in the first equation:
x + + z=0
x +
x +
x =
General solution:
Edwin