题目内容
用你喜欢的方法计算.
|
|
6-
|
2-
|
分析:(1)运用分数加法的运算定律进行简算,
(2)先算
加上
,再算减法,
(3)运用减法的运算定律进行简算,
(4)从左向右进行计算即可.
(2)先算
| 7 |
| 9 |
| 2 |
| 9 |
(3)运用减法的运算定律进行简算,
(4)从左向右进行计算即可.
解答:解:(1)
+
+
,
=
+(
+
),
=
+1,
=1
;
(2)
-
+
,
=
+
-
,
=1-
,
=
;
(3)6-
-
,
=6-(
+
),
=6-1,
=5;
(4)2-
+
,
=1
+
,
=1
.
| 2 |
| 3 |
| 3 |
| 4 |
| 1 |
| 4 |
=
| 2 |
| 3 |
| 3 |
| 4 |
| 1 |
| 4 |
=
| 2 |
| 3 |
=1
| 2 |
| 3 |
(2)
| 7 |
| 9 |
| 5 |
| 7 |
| 2 |
| 9 |
=
| 7 |
| 9 |
| 2 |
| 9 |
| 5 |
| 7 |
=1-
| 5 |
| 7 |
=
| 2 |
| 7 |
(3)6-
| 7 |
| 13 |
| 6 |
| 13 |
=6-(
| 7 |
| 13 |
| 6 |
| 13 |
=6-1,
=5;
(4)2-
| 5 |
| 7 |
| 2 |
| 7 |
=1
| 2 |
| 7 |
| 2 |
| 7 |
=1
| 4 |
| 7 |
点评:考查了分数四则混合运算的顺序,注意能运用运算定律进行简算的要简算.
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