Final answer:
To determine the number of people who attended the party based on a total bill of $625, we solve the equation f(x) = 15x + 25. Subtracting the reservation fee from the total gives us 600 = 15x, and dividing both sides by 15 results in x = 40, meaning the party consisted of 40 people.
Step-by-step explanation:
The question is asking to solve for the number of people x that attended a party, based on the total charge. The given function for the total charge is f(x) = 15x + 25. To find how many people went to the restaurant if the bill was $625, set the function equal to 625 and solve for x:
f(x) = 15x + 25
625 = 15x + 25
To solve for x, first subtract 25 from both sides to get:
600 = 15x
Then, divide both sides by 15 to find x:
x = 600 / 15
x = 40
Therefore, the party had 40 people.