Answer:
if you meant x squared the answer is 3x^2
Step-by-step explanation:
If f(x) is equal to 2x you can substitute x squared for f(x) and that would be x squared+x squared+x squared which is 3x^2
 
        
                    
             
        
        
        
Where are the expression. 
I would say -3+5
 
        
             
        
        
        
Answer:
45
Step-by-step explanation:
To find the number you just add 6 to 39 which gets you 45.
 
        
                    
             
        
        
        
Answer:
(x - 12)²/9
Step-by-step explanation:
y = 3sqr(x) + 12
Make x the subject:
y - 12 = 3sqrt(x)
(y - 12)/3 = sqrt(x)
Square both sides
(y - 12)²/9 = x
Interswitch variables
inverse function is:
(x - 12)²/9
If f(x) = (x + 12)^⅓
Then,
y = (x + 12)⅓
y³ = x + 12
y³ - 12 = x
f inverse:
x³ - 12