The general equation is that for every red tile, there must be 12 blue ones. 
Algebraically this is expressed as b = 12r where r is red and b is blue. Your teacher might like you to express it as y = 12x where y is blue and x is red. The meaning is the same.
For beginners it might be easier to say b = 12r. So if you have 15 reds then r = 15
b = 12 * r
b = 12 * 15
b = 180 blue tiles. 
 
        
                    
             
        
        
        
Answer:true
Step-by-step explanation:
 
        
                    
             
        
        
        
helped.
This answer was fact checked as TRUE by independent fact checkers
 
        
             
        
        
        
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Answer:
   The equation should be 8 (x minus 2.75) = 78, and she needs to sell each necklace for $12.50.
Step-by-step explanation:
The contribution margin of each necklace is the difference between its selling price (x) and its cost (2.75). Then the total profit from 8 necklaces would be ...
   8(x -2.75)
If Rita wants that profit to be $78, then she needs to solve the equation ...
   8(x -2.75) = 78 . . . . correct equation
The solution is ...
   x -2.75 = 9.75 . . . . divide by 8
   x = 12.50 . . . . . . . . add 2.75
She needs to sell each necklace for $12.50.