Liam, a garden shop owner, sells a variety of plants. He needs to determine the price for chrysanthemums that will earn the maximum profit for his business. After doing some research on how mums are priced by competitors, he arrives at the function
which models the relationship between units of mum sold in a week (x)
and the corresponding price (p).

Using the function x = 90 – 10p, you can see that the number of units of mums sold (x) varies with the price (p). As the price increases, the number of units sold decreases, as shown in the table. The price cannot be negative, so there are only nonnegative values for p. Likewise, the number of units sold cannot be negative, so the table includes only values of p that give a nonnegative output for x.

Liam wants to know how the function
would need to change to reflect the amount of money the business will take in. Use this function to model a function for gross sales. (Gross sales are the total amount of money the flowers sell for.)