题目内容
计算:
(1)(-3)0-
+|1-
|+
(2)(3
-2
+
)÷2
+(
)2
(3)
+
+
(4)(
-
)÷
.
(1)(-3)0-
| 27 |
| 2 |
| 1 | ||||
|
(2)(3
| 12 |
|
| 48 |
| 3 |
|
(3)
| b |
| a-b |
| a |
| a+b |
| 2ab |
| a2-b2 |
(4)(
| 2x |
| x-2 |
| x |
| x+2 |
| x |
| x2-4 |
考点:二次根式的混合运算,分式的混合运算,零指数幂
专题:计算题
分析:(1)根据零指数幂的意义和分母有理化得到原式=1-3
+
-1+
-
,然后合并即可;
(2)先把括号内的各二次根式化为最简二次根式,合并后进行二次根式的除法运算,然后进行加法运算;
(3)先通分得到原式=
+
+
,再进行同分母的分式的加法运算,然后把分子分解后约分即可;
(4)先把括号通分,再把分子分母因式分解和除法运算化为乘法运算,然后约分即可.
| 3 |
| 2 |
| 3 |
| 2 |
(2)先把括号内的各二次根式化为最简二次根式,合并后进行二次根式的除法运算,然后进行加法运算;
(3)先通分得到原式=
| b(a+b) |
| (a+b)(a-b) |
| a(a-b) |
| (a+b)(a-b) |
| 2ab |
| (a+b)(a-b) |
(4)先把括号通分,再把分子分母因式分解和除法运算化为乘法运算,然后约分即可.
解答:解:(1)原式=1-3
+
-1+
-
=-2
;
(2)原式=(6
-
+4
)÷2
+
=
÷2
+
=
+
=5;
(3)原式=
+
+
=
=
=
;
(4)原式=
•
=
•
=x+6.
| 3 |
| 2 |
| 3 |
| 2 |
=-2
| 3 |
(2)原式=(6
| 3 |
2
| ||
| 3 |
| 3 |
| 3 |
| 1 |
| 3 |
=
28
| ||
| 3 |
| 3 |
| 1 |
| 3 |
=
| 14 |
| 3 |
| 1 |
| 3 |
=5;
(3)原式=
| b(a+b) |
| (a+b)(a-b) |
| a(a-b) |
| (a+b)(a-b) |
| 2ab |
| (a+b)(a-b) |
=
| ab+b2+a2-ab+2ab |
| (a+b)(a-b) |
=
| (a+b)2 |
| (a+b)(a-b) |
=
| a+b |
| a-b |
(4)原式=
| 2x(x+2)-x(x-2) |
| (x-2)(x+2) |
| (x+2)(x-2) |
| x |
=
| x(x+6) |
| (x-2)(x+2) |
| (x+2)(x-2) |
| x |
=x+6.
点评:本题考查了二次根式的混合运算:先把各二次根式化为最简二次根式,再进行二次根式的乘除运算,然后合并同类二次根式.也考查了零指数幂和分式的混合运算.
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