For this case we have the following expression:
(4r / s) - (r / s)
We observe that we have the term r / s in the whole expression.
Therefore, we can draw common factor.
Rewriting we have:
(r / s) * (4-1)
(r / s) * (3)
3 (r / s)
Answer:
the difference is:
3 (r / s)
