Pls help!! Question:

The polynomial f (x) = ax2 + bx + c has zeros 4 and 5, and f (−1) = 60. Evaluate a, b and c.

Melanie is buying a bathing suit that costs 39.99. she is given a discount at the cash register of $6.00 when she scratched 15% off on a game piece for a store promotion. what will the sale price of melanie’s bathing suit be?