问题
解答题
计算: (1)0.027-
(2)(lg8+lg1000)lg5+3(lg2)2+lg6-1+lg0.006. |
答案
(1)0.027-
-(-1 3
)-2+(21 7
)7 9
-(1 2
-1)0=(0.33)-2
-1 3
+(1 (-
)21 7
)25 9
-1=1 2
-49+10 3
-1=-45;5 3
(2)(lg8+lg1000)lg5+3(lg2)2+lg6-1+lg0.006=(3lg2+3)•lg5+3(lg2)2-lg6+(lg6-3)=3lg2•lg5+3lg5+3(lg2)2-3
=3lg2(lg5+lg2)+3lg5-3=3lg2+3lg5-3=3-3=0.