Question

Помогите решить систему уравнений
$x - 2y + z - 4 = 0 \\ 2x + 2y - z - 8 = 0$

Answer 1

$\left \{ {{x-2y+z-4=0} \atop {2x+2y-z-8=0}} \right.\\\\+\left \{ {{x-(2y-z)=4} \atop {2x+(2y-z)=8}} \right.\\\\--------\\\\3x=12\\\\x=4\\\\-2y+z=0\\\\z=2y\\\\4--2y+2y-4=0\\\\y=0\\\\z=2*0=0$

Ответ : (4 ; 0 ; 0)