This Question: 4 pts 24 of 25 (20 complete) is Quiz: 114 pts p... Suppose that the price p, in dollars, and the number of sales, x, of a certain item follow the equation 6p + 3x + 3px = 69. Suppose also that p and x are both functions of time, measured in dp days. Find the rate at which x is changing when x = 3, p =4, and 1.2. dt The rate at which x is changing is sale(s) per day. (Round to the nearest hundredth as needed.)