Identify the Common Factors 12y^2+21y^5

Find the list of all common factors for ${\displaystyle 12y^2+21y^5}$ by finding the greatest common factor (GCF) for ${\displaystyle 12y^2+21y^5}$ and breaking it down to the list of common factors ${\displaystyle 1,3,y^2,y^1,3y^2}$. Then find all the possible combinations of these common factors, which are also common factors.