1/1x3+1/3x5.1/99x101要思路

问题描述:

1/1x3+1/3x5.1/99x101要思路

1/1x3+1/3x5.1/99x101
=1/2(1/1-1/3+1/3-1/5+...+199-1/101)
=1/2(1-1/101)
=50/101