题目内容
(1)化简:(2a
b
)(-3a -
b
)÷(-
a -
b -
)
(2)求值:(log43+log83)(log32+log92)-log
.
| 1 |
| 4 |
| 1 |
| 3 |
| 1 |
| 2 |
| 2 |
| 3 |
| 1 |
| 4 |
| 1 |
| 4 |
| 2 |
| 3 |
(2)求值:(log43+log83)(log32+log92)-log
| 1 |
| 2 |
| 4 | 32 |
考点:对数的运算性质,根式与分数指数幂的互化及其化简运算
专题:函数的性质及应用
分析:(1)利用分数指数幂的运算性质和运算法则求解.
(2)利用对数的换底公式和对数的运算性质和运算法则求解.
(2)利用对数的换底公式和对数的运算性质和运算法则求解.
解答:
解:(1)(2a
b
)(-3a -
b
)÷(-
a -
b -
)
=24a
-
+
b
+
+
=24b
.
(2)(log43+log83)(log32+log92)-log
=(log6427+log649)(log94+log92)+
=
•
+
=
•
+
=
+
=
.
| 1 |
| 4 |
| 1 |
| 3 |
| 1 |
| 2 |
| 2 |
| 3 |
| 1 |
| 4 |
| 1 |
| 4 |
| 2 |
| 3 |
=24a
| 1 |
| 4 |
| 1 |
| 2 |
| 1 |
| 4 |
| 1 |
| 3 |
| 2 |
| 3 |
| 2 |
| 3 |
=24b
| 5 |
| 3 |
(2)(log43+log83)(log32+log92)-log
| 1 |
| 2 |
| 4 | 32 |
=(log6427+log649)(log94+log92)+
| 5 |
| 4 |
=
| lg(27×9) |
| lg64 |
| lg8 |
| lg9 |
| 5 |
| 4 |
=
| 5lg3 |
| 2lg8 |
| lg8 |
| 2lg3 |
| 5 |
| 4 |
=
| 5 |
| 4 |
| 5 |
| 4 |
=
| 5 |
| 2 |
点评:本题考查对数式和指数式的求值,是基础题,解题时要注意运算性质和运算法则的合理运用.
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