Jerry makes souvenirs to sell in his shop. For one batch of souvenirs, he spends 200 dollars for materials and hopes to make 1,000 dollars in profit. He writes the equation pn−200 = 1,000 to represent the price, p, in dollars, for each souvenir and the number of souvenirs, n, that he needs to sell to make 1,000 dollars in profit. He knows that he can make at most 400 souvenirs from the materials.