问题
解答题
化简求值 (1)若x>0,化简 (2x
(2)计算:2(lg
|
答案
解析:(1)原式=(2x
)2-(31 4
)2-4x1-3 2
+4x-1 2
+1 2
=4x1 2
-27-4x1 2
+4=-23.1 2
(2)原式=lg
(2lg2
+lg 5)+2 (lg
)2-2lg2
+12
=lg
(lg 2+lg 5)+|lg2
-1|2
=lg
+(1-lg2
)=1.2