问题补充说明:1-2/3-2/9-2/27-2/81-2/243
【789气际电似核促取宪+789789+789789789】/纳败腊【987+987987+987987987】
=789*(1+1001+1001001)/[987*(1+1001+1来自001001)]
=789/987
=263/329
1-2/3-2/9-2/27-2/81-2/243
=1-(1-1/3)-(1/3-1/9)-(枯弊1/9-1/27)-(1/27-1/81)-(1/81-1/243)
=1-培1+1/3-1/3+1/洞滑9-1/9+1/27-1/27+1/81+1强破早速套正谈听/81-1/243
=1-1/243
=242/243