x+2y+3z=2x-y=3x+5y-6z xyz不為0 求x:y:z=?

2016-04-22 4:42 pm

回答 (2)

2016-04-22 7:22 pm
x + 2y + 3z = 2x - y = 3x + 5y - 6z

x + 2y + 3z = 2x - y ...... [1]
2x - y = 3x + 5y - 6z ...... [2]

由 [1]:
- x + 3y + 3z = 0 ...... [3]

由 [4]:
- x - 6y + 6z = 0 ...... [4]

[3] - [4]:
9y - 3z = 0
z = 3y

將 z = 3y 代入 [3] 中:
- x + 3y + 3(3y) = 0
x = 12y

所以 x : y : z
= 12y : y : 3y
= 12 : 1 : 3
2016-04-23 2:15 am
你好
x + 2y + 3z = 2x - y = 3x + 5y - 6z

x + 2y + 3z = 2x - y ...... [1]
2x - y = 3x + 5y - 6z ...... [2]

由 [1]:
- x + 3y + 3z = 0 ...... [3]

由 [4]:
- x - 6y + 6z = 0 ...... [4]

[3] - [4]:
9y - 3z = 0
z = 3y

將 z = 3y 代入 [3] 中:
- x + 3y + 3(3y) = 0
x = 12y

所以 x : y : z
= 12y : y : 3y
= 12 : 1 : 3


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