6. [-/5 Points] DETAILS The wholesale price p of e-tablet writing styluses in dollars is related to the supply x in thousands of units by 400p2 - x2 = 3591, If 3,000 styluses are available at the beginning of a week, and the price is rising at 15 cents per week, which one of the following statements is true? O Supply is rising at 60,000 styluses per week O Supply is rising at 80,000 styluses per week O Supply is falling at 60,000 styluses per week O Supply is falling at 70,000 styluses per week Supply is rising at 70,000 styluses per week 7. [-/5 Points] DETAILS The demand function for a certain brand of compact discs is given by P = -4x2 - 4x + 57 where p is the wholesale unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. Compute the elasticity of demand when x = 3. O 28/3 O 9/28 O 9/ 14 O 3/28 28/9