Question 952010:  Can someone please explain to me how to set up the equations for these. Thank you!
 
A catering service uses the function 
[c(x) = 300 + 17x/x] to determine the amount, in dollars, it charges per person for a sit-down dinner, where x is the number of people in attendance. 
(a) Find c(75) and explain what it represents. 
The company charges $ (Insert answer here )per person to cater a dinner for 75 people.
 
(b) Find c−1. 
c−1 =   
  
(c) Use c−1 to determine how many people attended a dinner for which the cost per person was $19.00. 
c−1($19.00) =   
 people 
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! A catering service uses the function 
 [c(x) = (300 + 17x)/x] to determine the amount, in dollars, it charges per person for a sit-down dinner, where x is the number of people in attendance. 
 (a) Find c(75) and explain what it represents. 
c(75) = (300+17*75)/75 = $21 
 The company charges $21 per person to cater a dinner for 75 people. 
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 (b) Find c^−1. 
 Interchange x and y to get:: 
(300 + 17*y)/y = x 
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Solve for y to get : 
300+17*c(x) = x*c(x) 
----- 
300 + 17y = yx 
17y-yx = -300 
y(x-17) = 300 
y = 300/(x-17) 
That is c^-1::: 
y is # of people 
x is cost per person 
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(c) Use c^−1 to determine how many people attended a dinner for which the cost per person was $19.00. 
 Solve:: 
y = 300/(x = 17) 
y = 300/(19-17) 
y = 300/2 
y = 150 people 
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Cheers, 
Stan H. 
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