题目内容
(1)
+
(2)
-
(3)
+
(4)
+
+
.
| 1 |
| 5 |
| 3 |
| 8 |
| 14 |
| 15 |
| 1 |
| 3 |
| 3 |
| 4 |
| 5 |
| 6 |
| 4 |
| 5 |
| 1 |
| 3 |
| 1 |
| 5 |
分析:(1)(2)(3)先通分,变成同分母的分数再相加减;
(4)根据加法交换律简算.
(4)根据加法交换律简算.
解答:解:(1)
+
=
+
=
;
(2)
-
=
-
=
=
;
(3)
+
=
+
=
;
(4)
+
+
.
=
+
+
,
=1+
,
=1
.
| 1 |
| 5 |
| 3 |
| 8 |
| 8 |
| 40 |
| 15 |
| 40 |
| 23 |
| 40 |
(2)
| 14 |
| 15 |
| 1 |
| 3 |
| 14 |
| 15 |
| 5 |
| 15 |
| 9 |
| 15 |
| 3 |
| 5 |
(3)
| 3 |
| 4 |
| 5 |
| 6 |
| 9 |
| 12 |
| 10 |
| 12 |
| 19 |
| 12 |
(4)
| 4 |
| 5 |
| 1 |
| 3 |
| 1 |
| 5 |
=
| 4 |
| 5 |
| 1 |
| 5 |
| 1 |
| 3 |
=1+
| 1 |
| 3 |
=1
| 1 |
| 3 |
点评:本题考查了基本的分数的加减混合运算,要注意分析数据,选择合适的简算方法简算.
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