I. 33% ii. don't know iii. unlikely iv. unlikely v. not likely vi. 90%
        
             
        
        
        
f(x) means the function of x 
so  the function is the input is x and the output is f(x), read "f of x". The output f(x) is sometimes given an additional name y by y = f(x). The example that comes to mind is the square root function on your calculator.
 
        
             
        
        
        
You would divide the new bikes by four to find out the amount of used bikes
so 15
        
                    
             
        
        
        
Answer: 
-x 7
Step-by-step explanation: