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(2007•泰安)若x1,x2是方程x2-2x-4=0的两个不相等的实数根,则代...
(2007•泰安)若x1,x2是方程x2-2x-4=0的两个不相等的实数根,则代数式2x12-2x1+x22+3的值是( )
A.19
B.15
C.11
D.3
考点分析:
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