题目内容
求值:
(1)(lg5)2+lg2•lg50;
(2)(2
)
-(-9.6)0-(3
)-
+(1.5)-2.
(1)(lg5)2+lg2•lg50;
(2)(2
| 1 |
| 4 |
| 1 |
| 2 |
| 3 |
| 8 |
| 2 |
| 3 |
分析:(1)直接利用对数的运算性质,求解即可.
(2)利用有理指数幂的运算性质求解即可.
(2)利用有理指数幂的运算性质求解即可.
解答:解:(1)(lg5)2+lg2•lg50
=(lg5)2+lg2•(lg5+1)
=(lg5)2+lg2•lg5+lg2
=lg5(lg5+lg2)+lg2
=lg5+lg2
=1.
(2)(2
)
-(-9.6)0-(3
)-
+(1.5)-2
=(
)
-1-(
)-
+(
)2
=
-1-(
)2+(
)2
=
.
=(lg5)2+lg2•(lg5+1)
=(lg5)2+lg2•lg5+lg2
=lg5(lg5+lg2)+lg2
=lg5+lg2
=1.
(2)(2
| 1 |
| 4 |
| 1 |
| 2 |
| 3 |
| 8 |
| 2 |
| 3 |
=(
| 9 |
| 4 |
| 1 |
| 2 |
| 27 |
| 8 |
| 2 |
| 3 |
| 2 |
| 3 |
=
| 3 |
| 2 |
| 2 |
| 3 |
| 2 |
| 3 |
=
| 1 |
| 2 |
点评:本题考查对数的运算性质,有理数指数幂的化简求值,考查计算能力.
练习册系列答案
相关题目