A and b are rational numbers. The difference between a and b is

Step-by-step explanation:

If a and b are rational and b is not zero, then a/b is also rational. Indeed, if a=m/n and b=p/q, where m, n, p, and q are integers, then a/b=mq/pn, i. e. it is also a ratio of two integers, and is therefore rational.