Alright First you combine the like terms. 
9n - 3n = 6n 
21 - 24 = -3 
Rewrite the simplified equation
6n - 3 = 0
Solve for n 
6n = 3 
n = 3/6 
n = 1/2 
Ask if you need more help! :)
        
             
        
        
        
Answer:
1st row 3 down
Step-by-step explanation:
 
        
             
        
        
        
Answer:
50/96
Step-by-step explanation:
I assume the table is:
![\left[\begin{array}{cc}Result&Total\\1&15\\2&13\\3&16\\4&17\\5&15\\6&20\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7DResult%26Total%5C%5C1%2615%5C%5C2%2613%5C%5C3%2616%5C%5C4%2617%5C%5C5%2615%5C%5C6%2620%5Cend%7Barray%7D%5Cright%5D)
Even numbers are 2, 4, and 6.  The total number of times she rolled an even number is 13 + 17 + 20 = 50.
So the probability is 50/96.
 
        
             
        
        
        
Answer:
here
Step-by-step explanation:
 
        
             
        
        
        
Answer:
x=18, y=9
Step-by-step explanation:
The lines of y+3 and 12 look equal to each other. So do x-3 and 15. Because of this, we set each equal to each other and solve. 
solving for x: 
x-3 = 15 
+ 3     +3 
x=18 
solving for y: 
y+3=12
- 3    -3
y=9
hope this helps!!!