一道分数简便计算题目
- 时间:2020-06-17 18:43:17
- 分类:数学世界
- 阅读:112 次
分享一道分数简便计算题目:1/(5×8)+1/(8×11)+1/(11×14)+1/(14×17)+……+1/(95×98)+1/(98×101)=?看到这个简便计算问题,不由得想起以前做过的1/(1×2)+1/(2×3)+1/(3×4)+1/(4×5)+……+1/(98×99)+1/(99×100)=?,当时是根据1/(1×2)=1-1/2,1/(2×3)=1/2-1/3,……把原题转化为:1-1/2+1/2-1/3+1/3-1/4+1/4-……+1/99-1/100,然后抵消中间的数,仅保留首尾,变成1-1/100=99/100。
今天这道题目的形式与原来那题很像,但也有不同的地方,即分母中相乘的两个数并不相邻,而是相差3,所以解题的方法就要发生相应的变化。先来看看其中一个加数吧!1/(5×8)=1/40,而1/5-1/8=3/40;1/(8×11)=1/88,1/8-1/11=3/88。也就是1/(5×8)并不等于1/5-1/8,而是等于(1/5-1/8)×1/3,其他加数也同样如此,这样我们便可以找出简便计算的方法了。请看下面的计算过程:
Using the OpenSSL command to Test the SSL Certificate Algorithm to Shuffle String in Python3 According to Index Depth First Search Algorithm to Find the Strobogrammatic Number Depth First Search Algorithm to Compute the Diameter of N-Ary Tr Remove the Temporary Files (including Windows.old) on Windows 10 Simulation Algorithm to Compute the Number of Water Bottles Using CloudFlare Worker Serverless Technology to Deploy a Load B Algorithms to Compute the Math Power(a, n) in logarithm Complexi Multithreading Testing using Pythons’ Low Level _threading Algorithm to Count the Number of Substrings With Only 1s
- 评论列表
-
- 添加评论