1/X(X+1)+1/(X+1)(X+2)+.+1/(X+8)(X+9)
=1/x-1/(x+1)+1/(x+1)-1/(x+1)+...+1/(x+8)-1/(x+9)
=1/x-1(x+9)
=9/x(x+9)
如追加其它问题,采纳本题后点击想我求助,①1/(1-X)+1/(1+X)+2/(1+X^2)+4/(1+X^4)②1/(1+X)+2/(1+X^2)+4/(1+X^4)+8/(1+X^8)如追加其它问题，采纳本题后点击想我求助，谢谢 祝学习进步！