Amy pays $1.71 in postage to mail a CD to a friend. She uses 41-cent stamps and 6-cent stamps. How many of each stamp did Amy use?

Which statement is true about the extreme value of the given quadratic equation? a. the equation has a maximum value with a y-coordinate of -21. b. the equation has a maximum value with a y-coordinate of -27. c. the equation has a minimum value with a y-coordinate of -21. d. the equation has a minimum value with a y-coordinate of -27.