Answer:
$13.67
Step-by-step explanation:
Let's say that CD= c and DVDs= d. Four CDs and 4 DVDs cost $164, so the equation will be:
i. 4c + 4d= 164
The cost of the 4 CDs is half the cost of the 4 DVDs, to put into an equation it will be:
ii. 4c= 0.5(4d)
4c= 2d
d= 2c
Then we can substitute the second equation (ii) into the first equation (i). The calculation will be:
4c + 4d= 164
4c + 4(2c)= 164
4c+ 8c= 164
12c= 164
c=13.67
The cost for each CD is $13.67