Answer:
R(x) = (460 * 7x)*(20+ x)
Explanation:
If exactly 20 people sign up :
Charge per person = $460
For passengers after 20:
At number of passengers = 20 ;
Cost = (fee * discount * number of additional passesengers) * (20 + Number of additional passengers
Let number of additional passengers after 20 = x
R(x) = ($460 * $7x) * (20 + x)
Hence,
R(x) = (460 * 7x)*(20+ x)