1⼀1990*1992+1⼀1992*1994+1⼀1994*1996+1⼀1996*1998+1⼀1998*2000=? 求算法过程

2024-12-30 09:12:04
推荐回答(1个)
回答1:

解:1/1990*1992+1/1992*1994+1/1994*1996+1/1996*1998+1/1998*2000
=1/2(1/1990 - 1/1992)+ 1/2(1/1992 - 1/1994)+...+ 1/2(1/1998 - 1/2000)
=1/2(1/1990 - 1/1992 + 1/1992 - 1/1994 +...+ 1/1998 - 1/2000)
=1/2(1/1990 - 1/2000)= 5/(1990*2000)= 1/796000