can some one please help me with this thanks

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 CDs you decide to buy. What is an expression in terms of C for the number of DVDs you buy?
B. what is an expression in terms of C for the cost of the CDs? for the cost of the DVDs?
c. Write and simplify an expression in terms of C for the total cost of all the gifts you buy. what properties of real numbers did you use to simplify the expression?

Question

can some one please help me with this thanks 

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 CDs you decide to buy. What is an expression in terms of C for the number of DVDs you buy?
B. what is an expression in terms of C for the cost of the CDs? for the cost of the DVDs?
c. Write and simplify an expression in terms of C for the total cost of all the gifts you buy. what properties of real numbers did you use to simplify the expression?

anonymous · Answer

a) If you are buying a total of 10 gifts, and c = # of CD's, then you are buying 10 - C dvd's. Agree?