A billboard designer has decided that a sign should have 5-ft margins at the top and bottom and 1 -ft margins on the left and right sides. Furthermore, the billboard should have a total area of 12500ft2 (including the margins). If x denotes the left-right width (in feet) of the billboard, determine the value of x that maximizes the area of the printed region of the billboard. x= feet Use this value of x to compute the maximum area of the printed region. Maximum area of printed region = square feet