楼主,问题里是不是有点小问题?应该是(1+1/2+1/3+1/4)*(1/2+1/3+1/4+1/5)-(1+1/2+1/3+1/4+1/5)*(1/2+1/3+1/4)吧?
先将(1+1/2+1/3+1/4)看作一个整体,将(1/2+1/3+1/4)看作一个整体,将1/5单独看作一个整体,则再去括号,式子就变成了,(1+1/2+1/3+1/4))*(1/2+1/3+1/4)+(1+1/2+1/3+1/4)*(1/5)-(1+1/2+1/3+1/4)*(1/2+1/3+1/4)-(1/5)*(1/2+1/3+1/4),整理可得(1+1/2+1/3+1/4)*(1/5)-(1/5)*(1/2+1/3+1/4),再将1看作一个整体,将(1/2+1/3+1/4)看作一个整体去括号得1*(1/5)+(1/2+1/3+1/4)*(1/5)-(1/5)*(1/2+1/3+1/4),所以最终结果为1*(1/5)即1/5
追问有点乱,能不能弄成列式啊
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