Theater has 108 seats, which are arranged in rows. The number of seats in each row is 3 less than the number of rows. How many rows of seats are in the theater.

Answer 1

let the number of rows be n
then the number of seats in each row is n-3

n(n-3) = 108
n^2 - 3n - 108=0
(n-12)(n+ 9) = -
n = 12 or n = -9 , but we can't have a negative number of rows

there are 12 rows