Let:
y = Total cost
x = Number of attendees
b = Flat fee = 104
a = Cost of books = $18
c = Payment of each attendee = $26
The cost function will be given by:
[tex]\begin{gathered} y=b+ax \\ y=104+18x \end{gathered}[/tex]The revenue function will be:
[tex]\begin{gathered} r=cx \\ r=26x \end{gathered}[/tex]In order to the company will be breaking even:
[tex]\begin{gathered} y=r \\ so\colon \\ 104+18x=26x \end{gathered}[/tex]Solve for x:
[tex]\begin{gathered} 26x-18x=104 \\ 8x=104 \\ x=\frac{104}{8} \\ x=13 \end{gathered}[/tex]It will take 13 attendees and the company's total expenses and revenues at that point is:
[tex]13\cdot26=338[/tex]$338
Answer:
13 attendees and $338