Need help with part a and b for this question

For a certain product, cost C and revenue R are given as follows, where x is the number of units sold in hundreds Cost: C =x + 1004x + 58 Revenue: 892(x - 3) + 25R" = 22,500 dC a. Find the marginal cost - - at x = 3 The marginal cost is estimated to be $ (Do not round until the final answer. Then round to the nearest hundredth as needed.) dR b. Find the marginal revenue at x = 3. The marginal revenue is estimated to be s (Do not round until the final answer. Then round to the nearest hundredth as needed.)