Question

A caterer charges $800 for a party of 25 guests. For a party of 60 guests, the cost is $1,430. Enter a linear model that represents the total cost, C, as a function of g, the number of guests at a party.

Answer 1

C = 18g +350

Explanation:

The 2-point form of the equation of a line is useful for this. For points (x1, y1) and (x2, y2), the equation is ...

y = (y2 -y1)/(x2 -x1)(x -x1) +y1

For points (25, 800) and (60, 1430), the line is ...

y = (1430 -800)/(60 -25)(x -25) +800

y = 630/35(x -25) +800

y = 18x +350

Using the variables required by the problem statement, this is ...

C = 18g +350