已知非零实数x,y,z满足方程组{4x-5y-2z=0,2x-y-4z=0,求x+2y-z⼀x+y+

已知非零实数x,y,z满足方程组{4x-5y-2z=0,2x-y-4z=0,求x+2y-z/x+y+z
2025-05-10 06:01:46
推荐回答(1个)
回答1:

(1)*2-(2)得 6x-9y=0,所以 x=3/2*y ,
代入(1)得 z=y/2 ,
所以 (x+2y-z) / (x+y+z)
=(3/2+2-1/2) / (3/2+1+1/2)
=1 。