1/2+1/6+1/12+1/20……1/9702+1/9900=?
问题描述:
1/2+1/6+1/12+1/20……1/9702+1/9900=?
急需会做的回一个 !
答
1/2+1/(2*3)+1/(3*4)+1/(4*5)------1/(98*99)+1/(99*100)=1/2+1/2-1/3+1/3-1/4+1/4-1/5------------+1/98-1/99+1/99-1/100=1/2+1/2+1/100=1+1/100