word problem
posted by Josh .
A College sold Advance tickets to a play at $4 per ticket. Anyone who attended and purchased a ticket at the door had to pay $5 a ticket. A total of 480 people attended the play, and the revenue (earnings) from the ticket sales was$ 2100. How many people bought tickets at the door?
ap + door=480
4*ap + 5*door=2100
in the first equation, ap= 480door
Put that into the second equation for ap, and then solve.

Let x =the number of people who paid at the door
4(480x)+5x=2100 Distribute
19204x+5x=2100 add like terms
19209x=2100
19209x=21001920
9x=180 Divide by nine
x=20 pe0ple at the door