1-1/2-1/6-1/12-1/20-.1/2011*2012
1-1/2-1/6-1/12-1/20-.1/2011*2012
解方程1/2+1/6+1/12+1/20+1/x(x+1)=2011/2012
1-1/2-1/6-1/12-1/20.-1/2011*2012
计算:1-2分之1-6分之1-12分之1-...-2011×2012分之1
|1/2014-1/2013|+|1/2013-1/2012|+|1/2012+1/2011|-|1/2011-1/20
|1/2-1|+|1/3-1/2|+|1/4-1/3|+...+|1/2012-1/2011|+|1/2013-1/20
1/2+1/6+1/12+1/20+.+1/9900
1/2,-1/6,1/12,-1/20,1/30
1/2+1/6+1/12+1/20+1/30
|1/2013-1/2012|+ |1/2012-1/2011|+|1/2011-1/2010|-|1/2010-1/2
(1/2012-1)(1/2011-1)(1/2010-1)...(1/3-1)(1/2-1)咋算
(2013/1-1)(2012/1-1)(2011/1-1).(3/1-1)(2/1-1)