由x/a+y/b+z/c=1得:bcx+acy+abz=abc；由a/x+b/y+c/z=0得:ayz+bxz+cxy=0；由ayz+bxz+cxy=0得:2abc(cxy+bxz+ayz)=0；展开,得：2abc^2xy+2ab^2cxz+2a^2bcyz=0.由bcx+acy+abz=abc,两边平方,得：a^2b^2c^2=a^2b^2z^2+b^2c...