Hi, I'm an employer of Brainly. Someone will answer you in the next 10 minutes. Thank you for your patience! Have a great day.
        
             
        
        
        
Answer:
D
Step-by-step explanation: its a coeficcient because itd a number that has a variable along with it 
 
        
                    
             
        
        
        
The complete set of common factors of 6 and 12 is D. {1,2,3,6}
        
             
        
        
        
Area of rectangular post card = length x width
For the given post card: 
length = 4 in
width = (3+b) in
area = 24 in^2
So, substituting in the equation of the area:
24 = 4 x (3+b)
24 = 12 + 4b
24 - 12 = 4b
12 = 4b
b = 3 in
Therefore:
the length of the postcard = 4 inch
the width of the postcard = b+3 = 3 + 3 = 6 inch
        
             
        
        
        
Step-by-step explanation:
5(3x+2)-2(4x-1)
15x+10-8x+2
7x+12