Which expression would represent the cost of one cd, if the total cost for three of them is $36?

The cost of three CD is 36. Set an equation. Let CD = c

3c = 36

To solve for the cost of one CD, isolate the c.

Note the equal sign. What you do to one side, you do to the other. Divide 3 from both sides

3c/3 = 36/3

c = 36/3

c = 12

The cost of one CD is $12.

hope this helps

C = 32/3

That expresses the total cost divided by the total number of CD's to give you the price of one CD.