Hi, I have the following problem.
"Prove that for any positive integers a, b, c, d satisfying
no cancellation is possible in the fraction
(a+c)/(b+d) (where the result of the fraction is a rational number."
Well, I know how to cancel a fraction, but how am I supposed to do this one, and what letters should I use to prove the cancellation?
I'd really appreciate it if you could give me a hand, thanks.