x-2y-z=1,z+4y+3z=1,x+4y+z=5方程的解

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x-2y-z=1,z+4y+3z=1,x+4y+z=5方程的解

x-2y-z=1,z+4y+3z=1,x+4y+z=5方程的解
x-2y-z=1,z+4y+3z=1,x+4y+z=5方程的解

x-2y-z=1,z+4y+3z=1,x+4y+z=5方程的解
解方程组
x-2y-z=1,……………………………………………………①
x+4y+3z=1,…………………………………………………②
x+4y+z=5……………………………………………………③
②-③,得 2z = - 4
即,z = - 2
把z = -2代回①、②,得
x - 2y = - 1
x + 4y = 7
解得 ,x=5/3,y=4/3
∴原方程组的解为 x=5/3,y=4/3,z = -2

z+4y+3z=1是否是x+4y+3z=1
如果是:
(1) x-2y-z=1
(2) x+4y+3z=1
(3) x+4y+z=5
(1)*2+()3,得:
3x-z=7(4)
(2)-(3),得:
2z=-4
z=-2
带入(4)得:
x=5/3

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z+4y+3z=1是否是x+4y+3z=1
如果是:
(1) x-2y-z=1
(2) x+4y+3z=1
(3) x+4y+z=5
(1)*2+()3,得:
3x-z=7(4)
(2)-(3),得:
2z=-4
z=-2
带入(4)得:
x=5/3
x=5/3,z=-2带入(1)得:
y=4/3

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