4x-3y=3z.(1)
x-3y=z.(2)
(1)-(2)得
3x=2z
x=(2/3)z
代入(2)得
(2/3)z-3y=z
y=-(1/9)z
则
xy+2yz/x²+y²+z²
=(2/3)(-1/9)+2(-1/9)/(4/9+1/81+1 )
=-24/118
=-12/59
4x-3y=3z.(1)
x-3y=z.(2)
(1)-(2)得
3x=2z
x=(2/3)z
代入(2)得
(2/3)z-3y=z
y=-(1/9)z
则
xy+2yz/x²+y²+z²
=(2/3)(-1/9)+2(-1/9)/(4/9+1/81+1 )
=-24/118
=-12/59