早教吧作业答案频道 -->数学-->
1/(3×4)+1/(4x5)+1/(5x6)+1/(6x7)+1/(7x8)+1/(8x9)=?
题目详情
1/(3×4)+1/(4x5)+1/(5x6)+1/(6x7)+1/(7x8)+1/(8x9)=?
▼优质解答
答案和解析
1/(3×4)+1/(4x5)+1/(5x6)+1/(6x7)+1/(7x8)+1/(8x9)
1/(a*b)=1/a-1/b
所以
=1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
因为中间部分互相抵消
就只剩1/3-1/9
所以=2/9
1/(a*b)=1/a-1/b
所以
=1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
因为中间部分互相抵消
就只剩1/3-1/9
所以=2/9
看了1/(3×4)+1/(4x5)...的网友还看了以下:
(6/5+8/5)X24还有8/3-15/7X8/3 2020-04-27 …
1/30=1/5x6=1/5-1/6,-----由此推测1/42=-----由此参考:1/6=1/ 2020-05-17 …
5x6除4+2.5x3除2中间是分数线下面是2x9除8+1x4.5除4用简便方法解 2020-05-17 …
帮我破解下这串数字什么意思9(2)4(3)6(2)2(1)4(3)3(1)4(3)9(1)6(3) 2020-05-17 …
1/2!2/3!﹢3/4!.﹢99/100!等于多少?感叹号代表阶乘,如:=1×2×3×4×5x6 2020-07-13 …
5x-4.5x6=5.5(4.5x6是4.5乘6) 2020-10-31 …
6/5X6/7-6/7÷5丨4-9/15÷9/5-2/3丨(1/2-1/3+1/4)X24丨5/8X 2020-10-31 …
5x6+x=4(6+x)用消元法解方程 2020-10-31 …
1/(3×4)+1/(4x5)+1/(5x6)+1/(6x7)+1/(7x8)+1/(8x9)=? 2020-10-31 …
用简便方法算(要过程的哦).74x10.1=()×()+()×()一.11又7/8-6又1/3-1又 2020-10-31 …