Answer:
X = {0, 1, 2, 3, 4}
Step-by-step explanation:
If X is the number of nonzero digits in a 4-digit PIN with no restriction on the digits, the pin can have up to 4 nonzero digits.
Let's see some examples:
If the PIN is 0000 then X = 4
If the PIN is 2045 then X = 3
If the PIN is 7546 then X = 0
From the previous examples, we can see that the possible values for X are 0, 1, 2, 3, 4. 
Thus X = {0, 1, 2, 3, 4}
 
        
             
        
        
        
Answer:
Option 3. y = 2x + 3
Step-by-step explanation:
wordssssss
  
        
                    
             
        
        
        
suppose 4:4:7 be 4x, 4x, 7x
or, 15x = 180° 
or, X = 180/15
or, X = 12
therefore, 
4x = 4x12= 48
4x= 4x12= 48
7x= 7x12= 84
so if you plus all of them you get 180