Question

One airline ticket costs $412. for each additional airline ticket sold to a group, the price of all the tickets is reduced by $4. Write a quadratic function that gives the initial cost of buying x tickets.

Answer 1

f(x)=104x-x^2

Explanation:

Let

x = number of tickets sold.

example, 2 tickets cost 2 · 408 = $816

3 tickets cost 3 · 404 = $738.

The cost of buying x tickets= the number of tickets sold × the price of each ticket.

If x tickets are sold, then the price of each ticket is 412-4(x-1)

Then the quadratic function that gives the total cost of buying x tickets is given by

Cost =quantity sold*price

=412-4(x-1)*x

=(412-4x+4)*x

=412x-4x^2+4x

=416x-4x^2

Divide through by 4

=104x-x^2

Therefore, the required quadratic function is

f(x)=104x-x^2