题目内容
脱式计算.
+
+
1-
-
1-(
+
)
-
+
.
| 1 |
| 6 |
| 1 |
| 3 |
| 1 |
| 4 |
1-
| 1 |
| 2 |
| 1 |
| 3 |
1-(
| 3 |
| 8 |
| 1 |
| 6 |
| 5 |
| 6 |
| 2 |
| 7 |
| 1 |
| 6 |
分析:本题根据异分母分数加法与减法的运算法则计算即可:异分母分数相加减,要先经过通分将异分母分数变为同分母分数后,再按同分母分数相加减的计算法则进行计算.算式(4)可据加法交律进行计算.
解答:解:(1)
+
+
,
=
+
+
,
=
,
=
;
(2)1-
-
,
=1-
-
,
=
;
(3)1-(
+
),
=1-(
+
),
=1-
,
=
;
(4)
-
+
,
=
+
-
,
=1-
,
=
.
| 1 |
| 6 |
| 1 |
| 3 |
| 1 |
| 4 |
=
| 2 |
| 12 |
| 4 |
| 12 |
| 3 |
| 12 |
=
| 9 |
| 12 |
=
| 3 |
| 4 |
(2)1-
| 1 |
| 2 |
| 1 |
| 3 |
=1-
| 3 |
| 6 |
| 2 |
| 6 |
=
| 1 |
| 6 |
(3)1-(
| 3 |
| 8 |
| 1 |
| 6 |
=1-(
| 9 |
| 24 |
| 4 |
| 24 |
=1-
| 13 |
| 24 |
=
| 11 |
| 24 |
(4)
| 5 |
| 6 |
| 2 |
| 7 |
| 1 |
| 6 |
=
| 5 |
| 6 |
| 1 |
| 6 |
| 2 |
| 7 |
=1-
| 2 |
| 7 |
=
| 5 |
| 7 |
点评:完成此类题目的关键是要细心,注意通分约分.
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