问题
解答题
(Ⅰ)求值:
(Ⅱ)已知:2a=5b=10,求
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答案
(Ⅰ)
-(16 81
)-27 8
+(2 3
-3
)0=2
-(4 9
)3×(-3 2
)+1=2 3
-(4 9
)-2+1=3 2
-4 9
+1=1.4 9
(Ⅱ)由2a=5b=10,得a=log210,b=log510,
所以
+1 a
=1 b
+1 log210
=lg2+lg5=lg10=1.1 log510