2018 AMC 8 第 5 题
先试着解答 2018 AMC 8 第 5 题，然后核对你的答案与视频与精心整理的解答，解答来自 LIVE by Po-Shen Loh。你也可以参加完整限时模拟考试、查看全部 2018 AMC 8 解答，或核对答案。
所有题目均经美国数学协会（MAA）官方合法授权使用。
5.
下列表达式的值是多少？
What is the value of
小提示：
把每个 之后的正奇数与它前面的偶数配对
Pair each positive odd number after with the even number just before it.
大提示：
配对之后，数一数还剩下多少个
Count how many ’s remain after pairing.
视频讲解：
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文字解答：
重新分组可得 每一项都等于 ，而这样的项共有 项，所以总和为 。
所以正确答案是 E。
Rearranging the terms, notice that the expression in the question is equal to: Each term is equal to and there are terms, so the total sum is
Thus, E is the correct answer.
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