挑战习题
1/5单选题
难度:

1.

如果椭圆的弦被点(4,2)平分,则这条弦所在的直线方程是(      )


A

B

C

D

提示1:
PHA+54K55beu5rOVPC9wPg==
提示2:
PHA+6K6+6ICM5LiN5rGCPC9wPg==
正确答案:RA==
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