Robert wants to throw a party for his friends. He has booked a banquet hall where he plans to serve dinner. The hall costs $200, and dinner costs $30 per person. If the final bill is p, which function gives the number of friends at the party.
We have
p = 200 + 30f where f is the number of friends.......so....subtract 200 from both sides
p - 200 = 30f divide both sides by 30
[ p - 200 ] / 30 = f
