5/72 is in simplest form, and can't be further reduced.
The simplest form of 45/72 is 5 over 8.
5 over 12
5/18
It is: 5/6
5/9
5/12.
5/24
5/9
GCD(45, 72) = 9 so the simplest form is (45/9) / (72/9) = 5/8
2/5 keep dividing it until its to its simplest form :)
8/5