So a b+d c is equivalent to C multiplied by the reciprocal of b+d and then multiplied by the reciprocal of A, and the result is C of a(b+d).

Similarly, a b+a c-a d is equivalent to multiplying D by the reciprocal of c-a, then multiplying b+a by the reciprocal of A, and the result is a d of a(b+a)(c-a).

One more thing needs to be explained. What you said above is ambiguous. For example, (1/5)/( 1/3) and 1/5/ 1/3 are different from the results, but they cannot be distinguished when reading. It's a little unclear to express the meaning in words. You can experience it. In fact, as long as the order is clear, it is quite simple.

For reference only.