Let

x = the number of seats in each row, x>0

y = the number of rows, y>0

The total number of seats is

x*y = 1920

The number of seats in each row exceeds the number of rows by 8 means:

x = y + 8

by solving the system of equations

x*y = 1920

x = y + 8

........

Click here to see the step by step solution

........

We find and consider only the positive solutions that is

x = 48 seats per row

y = 40 rows

in each row there are 48 seats.