Letters A B and C stand for three different digits What digit should replace each letter aba minus ca equal ab?

Oh, dude, let me break it down for you. So, we've got "aba" minus "ca" equals "ab." Since each letter represents a different digit, we can't have any repeats. So, "a" must be 1, "b" must be 9, and "c" must be 8. It's like math, but with a little twist.