Explain how a competitive profit-maximizing firm decides how much of each factor of production to demand?

A competitive profit-maximizing firm determines the quantity of each factor of production to demand by equating the marginal product of each factor to its marginal cost. The firm will continue to hire more of a factor as long as the additional revenue generated from that factor (marginal product times the price of the output) exceeds its cost. This process ensures that the firm utilizes resources efficiently to maximize profits. Ultimately, the firm adjusts its factor inputs until the marginal cost of each factor aligns with the added value it produces.