计算:a(a+1) +1/(a+1)(a+2) +1/(a+2)(a+3) + +1/(a+2004)(a+2005)
问题描述:
计算:a(a+1) +1/(a+1)(a+2) +1/(a+2)(a+3) + +1/(a+2004)(a+2005)
答
计算:a(a+1) +1/(a+1)(a+2) +1/(a+2)(a+3) + +1/(a+2004)(a+2005)