已知xyz满足4x减3y减6z=0x 2y-7z=0且xyz都不为零求x 2y 3z分之3x加2y z等于的值

2025-05-05 06:32:44
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已知xyz满足4x减3y减6z=0x 2y-7z=0且xyz都不为零求x 2y 3z分之3x加2y z等于的值
有4x-3y-6z=0
x +2y-7z=0得:
4x=3y+6z(1)
x =7z-2y(2)
(1)-(2)x4: 11y=22z
y=2z(3)
代入(2):x=3z(4)
因为xyz都不为零
所以(3x+2y+ z)/(x+ 2y +3z)

=(9z+4z+z)/(3z+4z+3z)
=(14z)/(10z)
=7/5

(3x+2y+ z)/(x- 2y -3z)

=(9z+4z+z)/(3z-4z-3z)
=(14z)/(-4z)
=-7/2