题目内容
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|
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分析:我们运用分数的四则混合的运算顺序进行计算,(1)(3)两级运算先做乘除后做加减.(2)有括号的先计算括号内部的,在计算括号外面的.
解答:解:(1)
×
+
÷
,
=
×
+
×
,
=
+
,
=
+
,
=
,
=
;
(2)
×[(
-
)÷
],
=
×[(
-
)×
],
=
×
,
=
;
(3)
-
+
×
,
=
-
+
,
=(
+
)-
,
=1-
,
=
.
| 7 |
| 13 |
| 5 |
| 6 |
| 6 |
| 8 |
| 13 |
| 6 |
=
| 7 |
| 13 |
| 5 |
| 6 |
| 3 |
| 4 |
| 6 |
| 13 |
=
| 35 |
| 78 |
| 9 |
| 26 |
=
| 35 |
| 78 |
| 27 |
| 78 |
=
| 62 |
| 78 |
=
| 31 |
| 39 |
(2)
| 5 |
| 14 |
| 3 |
| 4 |
| 2 |
| 5 |
| 5 |
| 4 |
=
| 5 |
| 14 |
| 15 |
| 20 |
| 8 |
| 20 |
| 4 |
| 5 |
=
| 5 |
| 14 |
| 7 |
| 25 |
=
| 1 |
| 10 |
(3)
| 7 |
| 8 |
| 4 |
| 5 |
| 3 |
| 8 |
| 1 |
| 3 |
=
| 7 |
| 8 |
| 4 |
| 5 |
| 1 |
| 8 |
=(
| 7 |
| 8 |
| 1 |
| 8 |
| 4 |
| 5 |
=1-
| 4 |
| 5 |
=
| 1 |
| 5 |
点评:灵活的运用分数四则混合运算的顺序进行计算即可.
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