Question

the total number of seats in an auditorium is modelled by the function f(x)=3x^2-5x where x is the number to f rows of seats. how many rows are there in the auditorium if it has a total of 518 seats

Answer 1

Answer: 14

Explanation:

`f(x) = 3x^2 - 5x`

`518 = 3x^2 - 5x`

`0 = 3x^2 - 5x - 518`

Use Quadratic formula with a = 3, b = -5, c = -518 to get:

x = 14, and -37/3

Since the number of rows cannot be negative, the answer must be positive. So there are 14 rows.