计算1/1x2+1/2x3+1/3x4+.+1/2011x2012 -3 -5 0 3 4选4个数算24点

问题描述:

计算1/1x2+1/2x3+1/3x4+.+1/2011x2012 -3 -5 0 3 4选4个数算24点

1/1x2+1/2x3+1/3x4+.+1/2011x2012
=1-1/2+1/2-1/3+1/3-1/4+...+1/2011-1/2012
=1-1/2012
=2011/2012

4x[3-(-3)]+0=24