题目内容
化简求值
(1)若x>0,化简 (2x
+3
)(2x
-3
)-4x -
(x-x
).
(2)计算:2(lg
)2+lg
•lg5+
.
(1)若x>0,化简 (2x
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(2)计算:2(lg
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(lg
|
解析:(1)原式=(2x
)2-(3
)2-4x1-
+4x-
+
=4x
-27-4x
+4=-23.
(2)原式=lg
(2lg
+lg 5)+
=lg
(lg 2+lg 5)+|lg
-1|
=lg
+(1-lg
)=1.
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(2)原式=lg
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(lg
|
=lg
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=lg
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