题目内容
计算:
(1)(π)0+(2
)0.5+0.1-2+(2
) -
+
;
(2)
lg
-
lg
+lg
.
(1)(π)0+(2
| 7 |
| 9 |
| 10 |
| 27 |
| 2 |
| 3 |
| 37 |
| 48 |
(2)
| 1 |
| 2 |
| 32 |
| 49 |
| 4 |
| 3 |
| 8 |
| 245 |
考点:对数的运算性质
专题:计算题,函数的性质及应用
分析:(1)(π)0=1,2
=
,2
=
,代入化简解得;
(2)利用指数运算及对数运算法则运算.
| 7 |
| 9 |
| 25 |
| 9 |
| 10 |
| 27 |
| 64 |
| 27 |
(2)利用指数运算及对数运算法则运算.
解答:
解:(1)(π)0+(2
)0.5+0.1-2+(2
) -
+
=1+(
)2×0.5+
+(
)3×(-
)+
=1+
+100+
+
=101+3=104;
(2)
lg
-
lg
+lg
=
lg32-
lg49-
×
lg8+
lg245
=
lg2-lg7-2lg2+
lg245
=
lg2+
lg245-lg7
=
lg490-lg7
=lg7+
-lg7
=
.
| 7 |
| 9 |
| 10 |
| 27 |
| 2 |
| 3 |
| 37 |
| 48 |
=1+(
| 5 |
| 3 |
| 1 |
| 0.12 |
| 4 |
| 3 |
| 2 |
| 3 |
| 37 |
| 48 |
=1+
| 5 |
| 3 |
| 9 |
| 16 |
| 37 |
| 48 |
=101+3=104;
(2)
| 1 |
| 2 |
| 32 |
| 49 |
| 4 |
| 3 |
| 8 |
| 245 |
=
| 1 |
| 2 |
| 1 |
| 2 |
| 4 |
| 3 |
| 1 |
| 2 |
| 1 |
| 2 |
=
| 5 |
| 2 |
| 1 |
| 2 |
=
| 1 |
| 2 |
| 1 |
| 2 |
=
| 1 |
| 2 |
=lg7+
| 1 |
| 2 |
=
| 1 |
| 2 |
点评:本题考查了指数与对数运算,属于中档题.
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