To express 09 as a fraction, we first need to understand that 09 is simply the number 9. Any whole number can be represented as a fraction by placing it over 1. Thus, we can write 9 as:
9 = 9/1
This fraction is already in its simplest form because the only common factor between 9 and 1 is 1 itself. Therefore, 09 as a fraction in simplest form is 9/1.