So you need to put numbers before each compound to make sure there are the exact same number of elements on each side. If you put a 4 before NH4 there are 4 Nitrogen and now 16 hydrogen. I just played around with numbers and guessed until I got them even.
        
                    
             
        
        
        
1000 is the answer to the queshtion
        
                    
             
        
        
        
Answer:
The most consistent mechanism is SN1.
Explanation:
The solvolysis of tert-butyl iodide in methanol will arise by the SN1  mechanism.
The reason for that is due the geometric structure of tert-butyl. The tertiary structure allows the formation of a stable carbocation, after the loss of the iodide ion. The carbocation will then be attacked by methanol molecules forming an eter.
 
        
             
        
        
        
ice because it can melt back to water