化简:1/xy+1/(x+4)(y+4)+1/(x+8)(y+8)+1/(x+12)(y+12)+……+1/(x+4n)(y+4n) 别去复制!

问题描述:

化简:1/xy+1/(x+4)(y+4)+1/(x+8)(y+8)+1/(x+12)(y+12)+……+1/(x+4n)(y+4n) 别去复制!

原题就是这样的吗? 原题不是这样的吧,x,y应该有个值,同学,你这样子提问不厚道呀.