题目内容
(1+
)×(1-
)×(1+
)×(1-
)×…×(1+
)×(1-
)= .
1 |
2 |
1 |
2 |
1 |
3 |
1 |
3 |
1 |
9 |
1 |
9 |
考点:分数的巧算
专题:计算问题(巧算速算)
分析:通过观察,把每个括号内的结果求出来,通过相互约分,只剩下
×
,进而解决问题.
1 |
2 |
10 |
9 |
解答:
解:(1+
)×(1-
)×(1+
)×(1-
)×…×(1+
)×(1-
)
=
×
×
×
×…×
×
=
×
=
故答案为:
.
1 |
2 |
1 |
2 |
1 |
3 |
1 |
3 |
1 |
9 |
1 |
9 |
=
1 |
2 |
3 |
2 |
2 |
3 |
4 |
3 |
8 |
9 |
10 |
9 |
=
1 |
2 |
10 |
9 |
=
5 |
9 |
故答案为:
5 |
9 |
点评:注意观察题目中数字构成的特点和规律,善于灵活运用运算技巧,巧妙解答.
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