Which costs more per issue, an 18-issue subscription for $40.50 or a 12-issue subscription for $33.60? explain.
(make sure to show your work and explain your solution plz.)

You have to divide total price by "18 times" for the first and by "12 times" for the second.

So, 

The 18-issue subscription costs per issue. 
The 12-issue subscription costs  per issue.

Therefore the 12-issue subscription costs more per issue.