system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: why is 4/0 irrational but 0/4 is rational?
gpt
Division is the inverse of multiplication.

20/5=4 because 5*4=20.

So the answer multiplied by the denominator is always equal to the numerator.

Now let’s look at the examples. 0/4=0 because 4*0=0. No problems there.

Consider 4/0 though. Let’s (falsely) assume it has an answer and give it the name Y. If 4/0=Y, then 0*Y=4. Can you find the number Y that multiplied by 0 gives you 4? You cannot because 0 times any number is 0 and hence why this is undefined. There is no solution.