m-2份之N=2 2M+3N=12用代如消元

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m-2份之N=22M+3N=12用代如消元m-2份之N=22M+3N=12用代如消元m-2份之N=22M+3N=12用代如消元n/(m-2)=2.12m+3n=12.2由1式得n=2m-4.3将3式代

m-2份之N=2 2M+3N=12用代如消元
m-2份之N=2 2M+3N=12用代如消元

m-2份之N=2 2M+3N=12用代如消元
n/(m-2)=2.1
2m+3n=12.2
由1式得
n=2m-4.3
将3式代入2式得
2m+3(2m-4)=12
2m+6m-12=12
8m=24
m=3
n=2m-4
n=2*3-4
n=6-4
n=2

2(M-2)+3N=8
同时除以M-2,再将M-2份之N=2 代入进去
左边是2+3x2=8
右边是m-2分之8
可得m-2=1,因此m=3

N/(M-2)=2 (1)
得N=2M-4 (3)
把(3)代入2M+3N=12(2)
2M+3X(2M-4)=12
2M+6M-12=12
M=0 (4)
(4)代入(3)
得N=-4