(a) I currently sell my merchandize at $50 per unit, at which sales price I sell 300 units each month. I intend to put the merchandize on sale and my market research shows that, for each $4 reduction in price, I will sell 25 more units each month. Express the reduction in my sales price as a linear function of my monthly demand (i.e. the number of units sold each month).

(b) Jane began a part-time job in the New Year and, at the end of January, she deposited $350 into her savings account (which already had some money in it). She deposited the same amount into her account at the end of every month from then on. After making her 8th deposit, at the end of August, with no money taken out from her account and no money added, other than her monthly $350 deposits, Jane had exactly $3,000 in her savings account. Express the amount of money in Jane’s savings account as a linear function of the number of months completed.