题目内容
3
-
+
+
5-
+
-1.
| 7 |
| 8 |
| 1 |
| 4 |
| 3 |
| 4 |
| 1 |
| 8 |
| 1 |
| 6 |
| 5 |
| 6 |
分析:适当调整运算顺序后进行结合,使计算变得简便.
解答:解:①3
-
+
+
,
=(3
+
)+(
-
),
=4+
,
=4
;
②5-
+
-1,
=(5-1)+(
-
),
=4+
,
=4
.
| 7 |
| 8 |
| 1 |
| 4 |
| 3 |
| 4 |
| 1 |
| 8 |
=(3
| 7 |
| 8 |
| 1 |
| 8 |
| 3 |
| 4 |
| 1 |
| 4 |
=4+
| 1 |
| 2 |
=4
| 1 |
| 2 |
②5-
| 1 |
| 6 |
| 5 |
| 6 |
=(5-1)+(
| 5 |
| 6 |
| 1 |
| 6 |
=4+
| 2 |
| 3 |
=4
| 2 |
| 3 |
点评:此题考查分数的加法和减法,运用计算法则进行计算,同时注意采取恰当的方法进行简算.
练习册系列答案
相关题目