4 packs of dvds can be bought with 48 dollars. How much does each pack cost?
There are 4 packs of DVDs. 
Each pack costs the same amount. 
The total cost of the 4 packs is 48 dollars. 

We can set this up as an equation: 

4x = 48

We can solve for x by dividing both sides by 4: 

x = 12

Each pack of DVDs costs 12 dollars.