# math

posted by
**Kimberly**
.

I do not undeerstand this question for homework.

Determine if the set is closed for the given operation.

1. yes or no- The set of positive fractions for division.

2. yes or no=The set of positive integers for subtraction.

Can someone help me? Is there a website that I can go to to explain this to me. I have had someone send me to a help site before but cannot remember it.

Thank you