NEED A, B AND C

Suppose that for a company manufacturing calculators, the cost, revenue, and profit equations are given by C = 90,000 + 30x, R=300x - 30, P=R-C where the production output in 1 week is x calculators. If production is increasing at a rate of 400 calculators per week when production output is 5,000 calculators. Find the rate of increase (decrease) in cost, revenue, and profit. at the rate of $12000 per week at this production level. A) Costs are increasing (Simplify your answer.) B) Revenue is (Simplify your answer.) at the rate of $ per week at this production level. at the rate of $ per week at this production level. C) Profits are (Simplify your answer.) . vi (1) More Enter your answer in each of the answer boxes