What is 5 divide by zero? but the answer is not zero?

5 divide by zero is Undefined.

That's right. The answer is not zero. In fact, there's no answer at all,

simply because there's no question. In math in general, division by zero

is "not permitted", and if people start talking about it, the answer is called

"indeterminate" ... that means vague, and can't be determined.

Division is repeated subtraction. 6 divided by 2 means: "How many times

can you take 2 away from 6 before the 6 is all used up and gone?", and the

answer is: 3 times and then it's gone.

So the question is really asking: "How many times can you take zero away

from 5 before the 5 is all used up and gone?". There's no answer, because

no matter how many times you take away zero, you can never use up the 5.

One more comment on the subject: Save your question marks. One is plenty.