X - ( 1 / 2 )x - ( 1 / 3)x = 6x / 6 - 3x / 6 - 2x / 6 = ( 1 / 6 )x, where x is full tank of gas  
The answer is 1 / 6 of the gas have left ;
        
             
        
        
        
Answer:

Step-by-step explanation:

 
        
             
        
        
        
Your answer would be $3,395.00. Hope this helps! :)
        
                    
             
        
        
        
Y 10x - 13 should be right
        
             
        
        
        
Given the function f (x) = 3x, find the value of f-1 (81).
 For this case, the first thing you should do is rewrite the function.
 We have then:
 y = 3 ^ x
 From here, we clear the value of x:
 log3 (y) = log3 (3 ^ x)
 log3 (y) = x
 Then, we rewrite the function again:
 f (x) ^ - 1 = log3 (x)
 Now, we evaluate the inverse function for x = 81:
 f (81) ^ - 1 = log3 (81)
 f (x) ^ - 1 = 4
 Answer:
 the value of f-1 (81) is: 
 f (x) ^ - 1 = 4