题目内容
(1)计算:2
+
+
-
;
(2)(
×
)6+
-4(
) -
-
×80.25-(-2012)0.
1 |
2 |
(-4)0 | ||
|
1 | ||
|
(1-
|
(2)(
3 | 2 |
3 |
(-2)2 |
16 |
49 |
1 |
2 |
4 | 2 |
分析:(1)化分数指数幂为根式,利用0指数幂的值等于1及分母有理化进行化简求值;
(2)化根式为分数指数幂,直接进行有理指数幂的化简.
(2)化根式为分数指数幂,直接进行有理指数幂的化简.
解答:解:(1)2
+
+
-
=
+
+
-1
=
+
+
+1-1
=
.
(2)(
×
)6+
-4(
)-
-
×80.25-(-2012)0
=22×33+2-4((
)2)
-2
×(23)
-1
=108+2-7-2
+
-1
=108+2-7-2-1
=100.
1 |
2 |
(-4)0 | ||
|
1 | ||
|
(1-
|
=
2 |
1 | ||
|
| ||||
(
|
=
2 |
| ||
2 |
2 |
=
5
| ||
2 |
(2)(
3 | 2 |
3 |
(-2)2 |
16 |
49 |
1 |
2 |
4 | 2 |
=22×33+2-4((
7 |
4 |
1 |
2 |
1 |
4 |
1 |
4 |
=108+2-7-2
1 |
4 |
3 |
4 |
=108+2-7-2-1
=100.
点评:本题考查了有理指数幂的化简与求值,考查了根式与分数指数幂的互化,解答此类问题的关键是熟记有关公式,此题是基础题.
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