Find the difference per row:
10 seats in the first row 
30 seats in the sixth row:
30 -10 = 20 seats difference.
6-1 = 5 rows difference.
 20 seats /  5 rows = 4 seats per row.
This means for every additional row, there are 4 more seats per row.
The equation would be:
Sn = S +(n-1)*d
Where d is the difference = 4
S = number of seats from starting row = 10
n = the number of rows wanted
S(11) = 10 + (11-1)*4
S(11) = 10 + 10*4
S(11) = 10 + 40
S(11) = 50
Check:
Row 6 = 30 seats
Row 7 = 30 + 4 = 34 seats
Row 8 = 34 + 4 = 38 seats
Row 9 = 38 + 4 = 42 seats
Row 10 = 42 + 4 = 46 seats
Row 11 = 46 + 4 = 50 seats.
 
        
             
        
        
        
Answer:
10p-30=40
Step-by-step explanation:
you distribute the number outside the () so 2p times 5 and 6 times 5 and you get 10p-30=40
 
        
             
        
        
        
Answer:
c
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
C =3.33x
Step-by-step explanation:
The cost of 1 barrette is 
9.99/3  sine it is 9.99 for 3 barrettes
or 3.33 per barrette
We want x barrettes
or 3.33*x
C is the total cost
C =3.33x
 
        
             
        
        
        
Answer:
Choice 1 is correct: 8/3 x 1/4 = 2/3
Step-by-step explanation: