I am going to build a chart this is best when using ratios 
              seniors    junior  total
                 7              4       
                 *?             *?     *?
    Totals                          121   
The way we fill out this chart is that we add the rows and multiply the columns. 
So we add 7 + 4 and fill it in our chart we get 11 
            seniors    junior  total
                 7              4       11
                 *?             *?     *?
    Totals                          121   
now to find the *? need to divide 121/11 to get *?
121/11 = 11
so now our chart looks like this 
            seniors    junior  total
                 7              4       11
                 11            11     11
    Totals                          121   
Now we multiply each column 
so 
7 * 11  = 77 
 4*11 = 44
now our chart look like this 
            seniors    junior  total
                 7              4       11
                 11            11     11
    Totals     77           44      121   
so seniors get 77 spaces 
and juniors get 44 spaces. 
        
             
        
        
        
Let x = number of adult tickets, and y = number of children tickets. One equation must deal with the number of tickets, and the other equation must deal with the revenue from the tickets.
Then x + y = 300 is the number of tickets
12x + 8y = 3280 is the revenue from the tickets.
Using the substitution method:
x + y = 300   ⇒   y = 300 - x   ⇒   Equation (3)
12x + 8y = 3280   ⇒   12x + 8(300-x) = 3280   ⇒   x = 220
y = 300 - x   ⇒   y = 300-220 ⇒ 80
Therefore 220 adult tickets and 80 children's tickets were sold. 
        
             
        
        
        
Answer:
C
Step-by-step explanation:
You have to divide both sides by the coefficient of x
 
        
                    
             
        
        
        
Answer:
Srry I need points to see answers :(
Step-by-step explanation: