Answer:
D hope this helps
Step-by-step explanation:
-y •2=-2 
-2+2=0
4x+x=5x
6+3=9
5x=9
9 divided by 5
x=1.9
So there for I think the answer is 2 it’s closest to 1.9
 
        
             
        
        
        
There is 4 cups in 1 quart.
        
             
        
        
        
Clue one tells you it ends in a 4 or 9. 
Clue two tells you it has to be 9. 
Clue three tells you x + 9 = 10
The number is 19