1/1x3+1/3x5+...1/9x11用简便方法怎么计算?

问题描述:

1/1x3+1/3x5+...1/9x11用简便方法怎么计算?

1/1x3+1/3x5+...1/9x11=1/2×(1-1/3)+1/2×(1/3-1/5)+…1/2×(1/9-1/11)=1/2-1/22=10/22=5/11