题目内容
能简算的要简算.
| 2-
|
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|
|
|
考点:分数的四则混合运算
专题:运算顺序及法则
分析:(1)先算小括号里的减法,再算括号外的加法;
(2)运用减法的性质进行简算;
(3)从左向右进行计算;
(4)先去括号,先算减去
,再减去
;
(5)先去括号,再从左向右计算;
(6)运用加法的交换律、结合律进行简算.
(2)运用减法的性质进行简算;
(3)从左向右进行计算;
(4)先去括号,先算减去
4 |
9 |
1 |
3 |
(5)先去括号,再从左向右计算;
(6)运用加法的交换律、结合律进行简算.
解答:
解:(1)
+(
-
)
=
+
=
;
(2)2-
-
=2-(
+
)
=2-1
=1;
(3)
-
+
=
+
=
;
(4)
-(
+
)
=
-
-
=
-
-
=
-
=0;
(5)
-(
-
)
=
-
+
=
+
=
;
(6)
+
+
+
=(
+
)+(
+
)
=1+
=1
.
4 |
5 |
3 |
8 |
1 |
4 |
=
4 |
5 |
1 |
8 |
=
37 |
40 |
(2)2-
3 |
7 |
4 |
7 |
=2-(
3 |
7 |
4 |
7 |
=2-1
=1;
(3)
5 |
8 |
1 |
3 |
5 |
12 |
=
7 |
24 |
5 |
12 |
=
17 |
24 |
(4)
7 |
9 |
1 |
3 |
4 |
9 |
=
7 |
9 |
1 |
3 |
4 |
9 |
=
7 |
9 |
4 |
9 |
1 |
3 |
=
1 |
3 |
1 |
3 |
=0;
(5)
5 |
12 |
1 |
12 |
1 |
2 |
=
5 |
12 |
1 |
12 |
1 |
2 |
=
1 |
3 |
1 |
2 |
=
5 |
6 |
(6)
11 |
12 |
5 |
8 |
1 |
8 |
1 |
12 |
=(
11 |
12 |
1 |
12 |
5 |
8 |
1 |
8 |
=1+
3 |
4 |
=1
3 |
4 |
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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