if a pc manufacturer has new models, at 450 a piece, and 25 sold per week. However, during a sale, it was droped to 350 a piece, and 75 were sold per week.

If (s) is the amount of units, and (x) is the price of a unit.....

1 - show that (x) and (s) are related, it wants me to do this using the following: s = 250 - (1/2)x

Im not very familiar with this, can anyone help?