Need help with this one is really confusing. i need an explanation with answer

1.

Suppose consumers will demand 70 units of a product when the price is $12.20 per unit and 25 units when the price is $20.20 each. Find the demand equation, assuming that it is linear. Find the price per unit when 35 units are demanded. Find the demand equation, where p is the price per unit and q is the quantity of units demanded. P = (Simplify your answer.)A bank account pays 5.7% annual interest, compounded monthly. How much must be deposited now so that the account contains exactly $16,000 at the end of four years? $ must be deposited now so that the account contains exactly $16,000 at the end of four years. (Do not round until the final answer. Then round to the nearest cent as needed.)