I don’t know your question sooo I’m just going to go based on what I know. 
980 - 725 = 225
$225 is how much you have left to buy games
In the end you can only buy about 3 games with $40 left
        
             
        
        
        
He's using the graduated cylinder method. I think the volume might be between 15 and 20. (It's kind of not obvious...)
        
             
        
        
        
Answer:
Draw a figure!
There are 6 surfaces to add.
4 of them have area 9*5 and 2 have area 5*4.
You should be able now to compute the surface areas.
Step-by-step explanation:
 
        
             
        
        
        
Answer:
the following are all equal
3/5 (x1)
6/10 (x2)
9/15 (x3)
12/20 (x4)
 
        
             
        
        
        
Answer:
x - 15
Step-by-step explanation: