Write the missing value above the variable. m-9=7

If you're for the value of "m"  then follow these steps to see what the answer is 

m - 9 - 7 = ?
? = 0 

Now, let's add the number 16 to the sides that you're working with 
Here's what I am talking about in case you don't know what I am talking  
m - 16 = 0
           + 16 
           -------
              16 

So, the value of m is 16 ; 


This is basic mathematics.Just practice your addition and subtraction facts in the problem like this 
 

Idon’t understand this but 90