Evaluating the expression 11C3 is very simple to do. 
If you are assuming that C is the notation for the combination. 
             11!
11C3= ____
     
            3!(11-3)!
        
             
        
        
        
Not sure if the 2 at the end is part of it all because with it the GCF can only be 1 
but,
the GCF of  24a, 3b and 36ab is 3.
        
                    
             
        
        
        
The answer is B.) x2-14x+2y 
 
        
                    
             
        
        
        
<u><em>Answer: </em></u>
#9: 5
#10: -2
#11: -1.5
<em><u>Step-by-step explanation:</u></em>
<em><u>#9:</u></em> 3,8,13,18,23,(28),(33),(38),.. <em>Go up by 5 each time, so the common difference is </em><u><em>5</em></u><em>.</em>
<u><em>#10:</em></u> 11,9,7,5,3,(1),(-1),(-3),... <em>Go down </em><em>(-)</em><em> by 2 each time, so the common difference is </em><u><em>-2</em></u><em>.</em>
<u><em>#11:</em></u> 3, 1.5, 0, -1.5, -3, (-4.5), (-6), (-7.5),... <em>Go down </em><em>(-) </em><em>by 1.5 each time, so the common difference is </em><u><em>-1.5</em></u><em>.</em>
 
        
             
        
        
        
-4.5 or -4.3 i’m not really sure i’m just estimating