10 A rectangular picture, ABCD, is placed inside a rectangular frame. The length, AB, of the picture is three times its height, x cm. The width of the frame is 2 cm. (a) The total area of the picture and the frame is 476 cm^2. Form an equation in x and show that it simplifies to 3x^2 + 16x - 460 = 0 . (b) Solve the equation 3x^2 + 16x - 460 = 0 . (c) Find the height and length of the frame. (d) The frame is made from wood. The wood is 5 mm thick. The mass of 1 cm^3 of the wood is 0.7 g. Calculate the mass of wood used in the frame.