Question

计算(a+b/ab)-(b+c/bc)

Answer 1

(a+b/ab)-(b+c/bc)
＝(1/b+1/a)-(1/c+1/b)
=1/a-1/c
=(c-a)/ca

Answer 2

c(a+b)-a(b+c)/abc
ca+bc-ab-ac/abc
bc-ab/abc
b(c-a)/abc
c-a/ac