A fast-food restaurant determines the cost and revenue models for its hamburgers. C = 0.6x + 7900, 0 S x s 50,000 1 R = 20,000 (67,000x - x2), OSX s 50,000 (a) Write the profit function for this situation. - x2 P = 20,000 - 2.75x - 7,900 X (b) Determine the intervals on which the profit function is increasing and decreasing. (Enter your answers using interval notation.) increasing (0, - 27,500) X decreasing (-27,500,00) X (c) Determine how many hamburgers the restaurant needs to sell to obtain a maximum profit. -27,500 X hamburgers Explain your reasoning. Because the function changes from decreasing to increasing at this value of x, the maximum profit occurs at this value. Because the function changes from increasing to decreasing at this value of x, the maximum profit occurs at this value. Because the function is always decreasing, the maximum profit occurs at this value of x. Because the function is always increasing, the maximum profit occurs at this value of x. The restaurant makes the same amount of money no matter how many hamburgers are sold. Need Help? Read It Watch It