The sales manager of the XYZ Store figured out that the demand item $x$ is

demand $=750-\frac{\text{r}\text{e}\text{t}\text{a}\text{i}\text{l}\text{p}\text{r}\text{i}\text{c}\text{e}}{4}$

Knowing that her profit from the sales of item $x$ is:

profit $=$ demand $($retail price $-$ wholesale price