You're just dividing the total yards of each felt evenly across the 3 quilts. 15/3 and 12/3 mean Ivan will use 5 yards of green felt and 4 yards of blue felt per quilt, for a total of 9 yards per quilt.
 
        
                    
             
        
        
        
The answer to number 7 is 7.5
 
        
                    
             
        
        
        
You multiply the denominator on one side of the equation by the numerator and vice versa. So for example(S)I'm going to multiply 4 by nine and 3 times n. Then that comes out to 3n=36. After you multiply, you divide from both sides to get the variable by itself. So you would divide both sides by 3 and you're final answer would be n=13. Hope this helped!
        
             
        
        
        
Answer:
C is correct if I'm doing the math right. best of luck!!