First list all the factors of 12;
1, 2, 3, 4, 6, 12
now let's see which ones are multiples of 3;
3, 6, 12 
so all we have left are numbers 1, 2 and 4.
hope that helps, God bless!
        
             
        
        
        
Answer:
a) x changes by 6.5 units
b) y changes by 13 units
Step-by-step explanation:
a. Over this interval, how much does x change by?
Initially, we have that x = 2.
In the end, we have that x = 8.5.
So x changes by 8.5-2 = 6.5 units
b. Over this interval, how much does y change by?
Initially, when x = 2, we have that y = 2x + 11 = 2*2 + 11 = 15
In the end, when x = 8.5, we have that y = 2*8.5 + 11 = 28
So y changes by 28 - 15 = 13 units
 
        
             
        
        
        
Ok
the sets are
natural numbers (or counting numbers), this is like 1,2,3,4,5 etc
whole numbers, this is including 0, so 0,1,2,3,4,5,6 etc
integers, this includes the previoius set and negatives, so -3,-2,-1,0,1,2,3,4,5 etc
rational numbers, this is the set of numbers that can be written in form a/b where b≠0, so all integers can be written like this, like example -3=-3/1, so -7/9 belongs here
-7/9 goes in the rational set
        
             
        
        
        
B and c, anything with an x^2 term is a quadratic.
        
                    
             
        
        
        
Answer: b 
Step-by-step explanation: There was the same question on brainly and they said that the submarine sandwich one was right.