Find the rate of change of total revenue, cost, and profit with respect to time. Assume that R(x) and C(x) are in dollars. R(x)equals40 x minus 0.5 x squared, C(x)equals4 x plus 15, when xequals25 and dx divided by dtequals20 units per day

Astudent found the solution below for the given inequality. |x-9|< -4 x-9> 4 and x-9< -4 x> 13 and x< 5 which of the following explains whether the student is correct? -the student is completely correct because the student correctly wrote and solved the compound inequality. -the student is partially correct because only one part of the compound inequality is written correctly. -the student is partially correct because the student should have written the statements using “or” instead of “and.” -the student is completely incorrect because there is no solution to this inequality.