问题
解答题
求值: (Ⅰ)(2
(Ⅱ)log9
|
答案
(Ⅰ)(2
)1 4
-(-7.8)0-(31 2
)3 8
+(2 3
)-22 3
=(
)9 4
-1-(1 2
)27 8
+(2 3
)23 2
=
-1-[(3 2
)3]3 2
+2 3 9 4
=
-1 2
+9 4 9 4
=
.1 2
(Ⅱ)log9
+lg20+log10025+5log524 27 3
=log93-
+1+lg2+log10252+21 4
=log323-
+1+lg2+log105+21 4
=
×(-1 2
)+1+lg2+1-lg2+21 4
=-
+4=1 8
.31 8