已知实数x满足4x2-4x+1=0,则代数式2x+12x的值为( ) A.2 B.-2 C.1 D.-1
问题描述:
已知实数x满足4x2-4x+1=0,则代数式2x+
的值为( )1 2x
A. 2
B. -2
C. 1
D. -1
答
∵实数x满足4x2-4x+1=0,
∴(2x-1)2=0,解得x=
1 2
∴原式=2×
+1 2
=1+1=2.1 2×
1 2
故选A.