Question

(Algebra 1, Unit 4, Lesson 5)C gives the cost, in dollars, of a cafeteria meal plan as a function of the number of mealspurchased, n. The function is represented by the equation C(n) = 4 + 3na. Find a value of n such that C(n)=31is true.Type the answer in the box below.C(n)31 is true when n =

Answer 1

For point a, you know that C(n) = 31 so you can plug this value into the equation and solve for n, like this

$\begin{gathered} C(n)=4+3n \\ 31=4+3n \\ \text{ Subtract 4 from both sides of the equation} \\ 31-4=4+3n-4 \\ 27=3n \\ \text{ Divide both sides of the equation by 3} \\ \frac{27}{3}=\frac{3n}{3} \\ 9=n \end{gathered}$

Therefore, the value of n such that C (n) = 31 is true is n = 9.

For the point b, since the given function corresponds to a cafeteria meal plan based on the number of meals purchased, n, then a value of 9 for n indicates that a meal plan that has 9 meals will be worth $ 31.