At a store 20 feet of fencing cost $36 at the rate how much will 15 feet of fencing cost

The table shows a pattern of exponents. what is the pattern as the exponents decrease?

Which of the following tables represents exponential functions?

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning