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要用配方法解一元二次方程x2-4x-3=0,那么下列变形的结果中正确的是( ) ...
要用配方法解一元二次方程x2-4x-3=0,那么下列变形的结果中正确的是( )
A.x2-4x+4=9
B.x2-4x+4=7
C.x2-4x+16=19
D.x2-4x+2=5
考点分析:
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方程2(x-1)
2=
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的根为( )
A.x
1=1+
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,x
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B.x
1=
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+1,x
2=
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-1
C.x
1=
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2=
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2-
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A.(-
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2B.(-
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2D.(
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C.-8或9
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D.无解
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