$60 ÷ $15 = 4
$9 × 4 = $36
he saved $36 when he earned $60
        
             
        
        
        
They are inverses. 
The easiest way to solve this is to take the g(x) equation and switch the g(x) with the x. Then solve for your new g(x). Since it looks just like f(x) after doing that, it is an inverse. 
        
             
        
        
        
Answer:
You are building your kids a small desk, where the width is 1/3 of its length. The length of the desk is 6 feet. What is it’s width? What is the area of the desk?
        
             
        
        
        
No solution is  the correct answer i  think