Question

*20 POINTS*

The total number of seats in an auditorium is modeled by f(x) = 2x^2 - 6x, where x represents the number of rows of seats. How
many rows are there in the auditorium if it has a total of 540 seats?

A) 15
B) 22
C) 30
D) 18

Answer 1

D) 18

Explanation:

2x² - 6x = 540

2x² - 6x - 540 = 0

(2x + 30)(x - 18) = 0

x - 18 = 0

x = 18

2x + 30 = 0

2x = -30

x = -15; this cannot be the answer as it is negative