题目内容
计算
(1)(-
)-1-23×0.125+(
-2012)0
(2)(
)2÷(
)2•
(3)
+
-
(4)(
-
)•
÷(
+
).
(1)(-
1 |
2 |
3 | -27 |
(2)(
-a |
b |
2a2 |
5b |
a |
5b |
(3)
m+2n |
n-m |
n |
m-n |
2n |
n-m |
(4)(
x |
x-y |
2y |
x-y |
xy |
x-2y |
1 |
x |
1 |
y |
分析:(1)首先计算乘方,然后计算乘法,最后进行加减运算即可求解;
(2)首先计算乘方,然后把除法转化成乘法,然后进行乘法运算即可;
(3)首先通分,然后进行同分母的分式的加减运算即可;
(4)首先计算括号内的分式,然后把除法转化成乘法,最后进行乘法运算即可.
(2)首先计算乘方,然后把除法转化成乘法,然后进行乘法运算即可;
(3)首先通分,然后进行同分母的分式的加减运算即可;
(4)首先计算括号内的分式,然后把除法转化成乘法,最后进行乘法运算即可.
解答:解:(1)原式=-2+8×0.125+1
=-2+1+1
=0;
(2)原式=
÷
•
=
•
•
=
;
(3)原式=
-
-
=
=
=-1;
(4)原式=
•
÷
=
•
•
=
.
=-2+1+1
=0;
(2)原式=
a2 |
b2 |
4a4 |
25b2 |
a |
5b |
=
a2 |
b2 |
25b2 |
4a2 |
a |
5b |
=
5a |
4b |
(3)原式=
m+2n |
n-m |
n |
n-m |
2n |
n-m |
=
m+2n-n-2n |
n-m |
=
m-n |
n-m |
=-1;
(4)原式=
x-2y |
x-y |
xy |
x-2y |
x+y |
xy |
=
x-2y |
x-y |
xy |
x-2y |
xy |
x+y |
=
x2y2 |
x2-y2 |
点评:本题考查分式的混合运算,关键是通分,合并同类项,注意混合运算的运算顺序.
练习册系列答案
相关题目