The marginal revenue and marginal cost functions of a company are MR = 30 − 6x and MC = −24 + 3x where x is the product, then the profit function is
9x2 + 54x
9x2 − 54x
54x - \(\frac { { 9x }^{ 2 } }{ 2 } \)
54x - \(\frac { { 9x }^{ 2 } }{ 2 } \) + k