计算:4/ (x+1)(x+3)+4/(x+3)(x+5)+…..+4/(x+2n-1)(x+2n+1)的值?
问题描述:
计算:4/ (x+1)(x+3)+4/(x+3)(x+5)+…..+4/(x+2n-1)(x+2n+1)的值?
能不能说详细一点哟——fish俊
答
4/ (x+1)(x+3)=2/(x+1) -2/(x+3)
4/ (x+1)(x+3)+4/(x+3)(x+5)+…..+4/(x+2n-1)(x+2n+1)
=2/(x+1) -2/(x+2n+1)