you are buying gifts for 10 people. you decide to buy each person either a cd or a dvd. a cd costs $12 and a dvd costs $20.
a. let c = the number of cd's you decide to buy. what is an expression in terms of c for the numbers of dvd's you buy?
b. what is an expression in terms of c for the costs of the cd's for the cost of the dvd's?
c. write and simplfy an expression in terms of c for the total costs of all the gifts you buy. what properties of real numbers did you use to simplify the expression?

Question

you are buying gifts for 10 people. you decide to buy each person either a cd or a dvd. a cd costs $12 and a dvd costs $20. 
a. let c = the number of cd's you decide to buy. what is an expression in terms of c for the numbers of dvd's you buy?
b. what is an expression in terms of c for the costs of the cd's for the cost of the dvd's?
c. write and simplfy an expression in terms of c for the total costs of all the gifts you buy. what properties of real numbers did you use to simplify the expression?