A. A rectangle, with an open top, has a perimeter of 56 cm. Find the dimensions of the rectangle that maximize its area.
B. What can you say about the dimensions that minimize the area?
2. A. Let x and y be two real numbers such that y - 2x = 20 and (3 - x)(y + 2) is a maximum. Find x and y.
B. Suppose that one of these numbers is 6. What is the second one? Why?