Question

Devante has a lunch account in the school cafeteria His starting balance at the beginning of the month is $35.50. The first wook, Davante bought 3 lunches and his account balance was $28.00. The second week. Devante

bought 5 lunches and his account balance was 515 50

In a model that relates the balance of his lunch account as a function of the number of lunches he buys, what does the rate of change represent?


A: the number of lunches he purchases


B: the starting balance of his lunch account


C: the amount of money in his lunch account


D: the amount of money he pays for each lunch

Answer 1

D the amount of money he pays for each lunch

Explanation:

In each lunch Devante has, he pays 2,50 $ according to:

Money in t = t₀ he has 35,50 $ paid 3 lunches and spent

35,50 - 28 = 7,5

Then the cost of each lunch is 7,5 / 3 = 2,5 $

After that

bought 5 lunches and spent 28 - 15,5 = 12,50

Again 12,5 / 5 = 2,5 $

Now the model for the situation is a straight line with a slope 2,5

In an x , y cartesian system in which y is money in the account and x is the number of lunches, such a straight line will be

y = b - m*x ( b the intercept on y and m the negative slope)

y = 35,50 - 2,5*x

So answering the question is lyrics D the amount of money he pays for each lunch