Answer:
Yes you can! 9/10 is the simplest form.
Explanation:
If you look at 27 and 90, they share a common factor of 9. So, by dividing each of these numbers by 9, we can find the simplest form, 9/10. Furthermore, we can confirm this is the simplest form because the first digit is one number away from the second, and therefore unable to be simplified any further.