Answer: I got 50x+$75 but I’m not too sure for the last step 
Step-by-step explanation:
 
        
             
        
        
        
Step-by-step explanation:
y = .10d + .25q
y is the total amount, if you have d dimes and q quarters
 
        
             
        
        
        
The rate of change is 6 secs/foot in terms of seconds per foot. 
        
             
        
        
        
You subtract 5 to the other side so it'll read -6n=-4 then divide -6 to the other side and it'll be 2/3