4/20 = 1/5
9/24 = 3/8
18/30 = 3/5
9/12 = 3/4
9/21 = 3/7
5/45 = 1/9
20/25 = 4/5
10/12 = 5/6
6/9 = 2/3
4/40 = 1/10
Step-by-step explanation:
Find the greatest common factor then divide the numerator and denominator by the greatest common factor
Hope This Helps :)