a+1/b=b+1/c=c+1/a同乘abca²bc+ac=ab²c+ab=abc²+bca²bc+ac=ab²c+ab两边除以aabc+c=b²c+bbc(a-b)=b-c (1)同理ac(b-c)=a-c (2)ab(a-c)=a-b (3)相乘(abc)²(a-b)(b-c)(a-c)=(a-b)(b-...