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已知x,y∈R,且x+2y≥1,则二次函数式u=x2+y2+4x-2y的最小值为...
已知x,y∈R,且x+2y≥1,则二次函数式u=x
2+y
2+4x-2y的最小值为.( )
A.-3
B.
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C.24
D.
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