1⼀1*2+1⼀2*3+1⼀3*4+...+1⼀2012*2013

1⼀1*2+1⼀2*3+1⼀3*4+...+1⼀2011*2012+1⼀2012*2013也可以
2024-12-22 00:55:01
推荐回答(3个)
回答1:

解:∵1/1×2=1-1/2
1/2×3=½-1/3
。。。
1/2012×2013=1/2012-1/2013
∴1/1*2+1/2*3+1/3*4+...+1/2011*2012+1/2012*2013
=1-1/2+1/2-1/3+1/3-1/4+...+1/2011-1/2012+1/2012-1/2013
=1-1/2013
=2012/2013

回答2:

1/1*2+1/2*3+1/3*4+...+1/2011*2012+1/2012*2013
=1-1/2+1/2-1/3+1/3-1/4+...+1/2011-1/2012+1/2012-1/2013
=1-1/2013
=2012/2013

回答3:

2012