x=2,y=1 1/xy+1/(x+1)(x+1)+1/(x+2)(y+2)+...
问题描述：
x=2,y=1 1/xy+1/(x+1)(x+1)+1/(x+2)(y+2)+...
x=2,y=1 1/xy+1/(x+1)(x+1)+1/(x+2)(y+2)+.+1/(x+2010)(y+2012) 最后等于多少
答
x=2,y=1
1/xy+1/(x+1)(y+1)+1/(x+2)(y+2)+.+1/(x+2010)(y+2012)
=1/2*1+1/(2+1)(1+1)+1/(2+2)(1+2)+.+1/(2+2010)(1+2012)
=1/2*1+1/3*2+1/4*3+.+1/2012*2013
=1-1/2 +1/2-1/3+1/3-1/4+...+1/2012-1/2013
=1-1/2013
=2012/2013�����Ӧ����y��2010�����������鷳����һ�顣������x=2,y=11/xy+1/(x+1)(y+1)+1/(x+2)(y+2)+.....+1/(x+2010)(y+2010)=1/2*1+1/(2+1)(1+1)+1/(2+2)(1+2)+.....+1/(2+2010)(1+2010)=1/2*1+1/3*2+1/4*3+.....+1/2012*2011=1-1/2 +1/2-1/3+1/3-1/4+...+1/2011-1/2012=1-1/2012=2011/2012