1/3 x - 1/2 = 18 1/2 
1/3 x = 19 (add 1/2 on the right side to 18 1/2) 
x = 57 (multiply the reciprocal of 1/3 and that will be 3/1 or 3 to 19 to get x by itself) 
So, the answer is x = 57 (d. 57)
        
             
        
        
        
Here the my solutions,hope you understand
 
        
        
        
Answer:
D.
Step-by-step explanation:
The number which multiplies x  is the slope of the graph so 13x becoming  3x means the slope of the graph will change.