通分太麻烦雀如枯了橡橘!简便一点的方法:解顷洞:(x71)/(x7)-(x61)/(x6)=(x91)/(x9)-(x81)/(x8).1(1/x7)-1-(1/x6)=1(1/x9)-1-(1/x8).(x7)*(x6)=(x9)*(x8)解方程得x=-7.5