Answer:

Explanation:
The reason why

isn't a rational number is because, when simplified, it results in 9.848857802.... its decimal doesn't terminate(stop).
The reason why

isn't a rational number is because, when simplified, it results in 9.899494937.... it's decimal doesn't terminate(stop).
The reason why

isn't a rational number is because, when simplified, it results in 9.949874371.... it's decimal doesn't terminate(stop).
The reason why

is a rational number is because, when simplified, it results in 10, its decimal terminates (stops).