Leanne has a gas card that has $150 on it. She spends $25 a week on gas. What is the recursive rule that represents the amount of money she has on her gas card after the first week.

Question

A. f(n) = f(n-2)-25, given f(1) = 150

B. f(n) = f(n-1)-150, given f(1) = 25

C. f(n) = 6f(n-1)-25, given f(1) = 25

D. f(n) = f(n-1)-25, given f(1) = 150

Answer 1

Hello Sri.,

I see that you have submitted 2 questions of this type plus some others. If you have a number of questions, you may want to hire a tutor.

In this question, you start with the $150 which is the starting amount f(1). Now figure out what you would have after 1 week. That would be f(2). The formula will show more generally what you do each week to the number from the previous week. The n represents the number of weeks and the f represents the dollars on the gas card. Really n is the x and f is the y.

In the answers, f(n) would be the new dollar amount and f(n - 1) would be the dollar amount from the previous week.