Identify the gcf of the polynomial 6xy-30x2y4

Can someone me out here number 4 plz

Part a: sam rented a boat at $225 for 2 days. if he rents the same boat for 5 days, he has to pay a total rent of $480. write an equation in the standard form to represent the total rent (y) that sam has to pay for renting the boat for x days. (4 points)

Choose the more precise measurement. 26.4 cm or 8.39 cm