DONT USE FOR POINTS PLZ

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

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)

Find the zeros of each function. f(x) = 6x^2 - 7x - 20