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已知x,y满足线性约束条件,若=(x,-2),=(1,y),则z=•的最大值是(...
已知x,y满足线性约束条件
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102711456550204/SYS201311031027114565502006_ST/0.png)
,若
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=(x,-2),
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=(1,y),则z=
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•
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的最大值是( )
A.-1
B.
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C.7
D.5
考点分析:
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