答案为1/8.b-a=1,c-a=2,c-b=1.a/bc + b/ca + c/ab - 1/a - 1/b - 1/c=a/bc + b/ca + c/ab -b/ab-c/bc-a/ca=a/bc-c/bc+b/ca-a/ca+c/ab-b/ab=(a-c)/bc+(b-a)/ca+(c-b)/ab=(a(a-c)+b(b-c)+c(c-b))/abc=(-2a+b+c)/abc=(b...