The total number of seats in the auditorium=1428
Let, the number of rows be=x
Then the number of seats in each row will be=x+8
Then the equation will be:
x(x+8)=1428
x*x+8x-1428=0
On solving(use your calculator) the values of x=34,-42
Since the number of rows cannot be negative we take positive number which is x=34
Then the number of seats in each row=34+8=42 which is the required answer