来自方高林的问题
【1/x(x+1)(x+2)+1/(x+1)(x+2)(x+3).+1/(x+98)(x+99)(x+100)=?】
1/x(x+1)(x+2)+1/(x+1)(x+2)(x+3).+1/(x+98)(x+99)(x+100)=?
1回答
2020-05-31 21:51
【1/x(x+1)(x+2)+1/(x+1)(x+2)(x+3).+1/(x+98)(x+99)(x+100)=?】
1/x(x+1)(x+2)+1/(x+1)(x+2)(x+3).+1/(x+98)(x+99)(x+100)=?
1/x(x+1)(x+2)+1/(x+1)(x+2)(x+3).+1/(x+98)(x+99)(x+100)=(1/2){[1/x(x+1)-1/(x+1)(x+2)]+[1/(x+1)(x+2)-1/(x+2)(x+3)]+.+[1/(x+98)(x+99)-1/(x+99)(x+100)]}=(1/2){1/x(x+1)-1/(x+99)(x+100)}=[(x+99)(x...