Posted by Jeannie on .
A rectangular auditorium seats 900 people. The number of seats in each row exceeds the number of rows by 11. Find the number of seats in each row.

Algebra II 
Lena,
Total # of seats = 900
# of rows = R
# of seats = S
So according to the question, if we have R rows then we have R+11 seats
Total # of seats = # of rows * # of seats/row
900 = R * (R+11)
900 = R^2 + 11R
0 = R^2 + 11R 900
0 = (R+36)(R25)
Therefore, you must have 25 rows with 36 seats in each row. We can't use 36 rows because it does not give us a realistic answer. 
Algebra II 
Lena,
Essentially we've created a quadratic equation and we're solving it using factoring. If you don't understand how I solved this question, I can expand on my thinking. Let me know if it makes sense.