3bc is the answer to your problem
 
        
                    
             
        
        
        
X - 6y=18     
2x-3y=9    |*-2
   x -6y=18
-4x+6y=-18
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-3x=0, x=0
2x-3y=9
2*0-3y=9
-3y=9, y=-9/3, y= -3
        
             
        
        
        
Answer:
1/10
Step-by-step explanation:
 
        
             
        
        
        
You want to do to one side the same thing you do to the other side.
In order to get the n by itself you divide the 25n by 25. But in order to not change the answer you need to do the same to the 70.

so n=

 which can be reduced to 

so n=
