You will need to add 3 to each side.
x^2-3=15
     +3   +3
x^2=12
and go from there
 
        
                    
             
        
        
        
Answer:
29
Step-by-step explanation:
f(x) = 4x -7
f(9) = 4(9)-7
=36-7
=29
 
        
             
        
        
        
Answer:
no
Step-by-step explanation:
 
        
             
        
        
        
Answer:

The file includes the input of your equation, comment if the equation you input is a mistake. 
 
        
                    
             
        
        
        
78×.33=25.74 busses are new
25.74+15=40.74 new busses
78+15=93 total busses
40.74/78=0.5223076923= 52% will be new with the new 15 busses