The revenue (in thousands of dollars) from producing x units of an item is modeled by R(x) = 12x -0.005x^2.Find the average rate of change in revenue as x changes from 1001 to 1008. The average rate of change in revenue is ____ dollars per unit. (Do not round until the final answer. Then round to the nearest integer as needed.)I just need to know how to solve this problem, I know the answer. Thank you!