There are 15 people in the chorus. Each year, the number of people in the chorus increases by 3. There are 30 people in the band. Each year, 2 new people join the band. Part A: Write a function to represent the number of people in the chorus throughout the years.
Part B: Write a function to represent the number of people in the band throughout the years.
Part C: How many people are in the chorus after 9 years? How many people are in the band after the same number of years?
Part D: After approximately how many years is the number of people in the chorus and the number people in the band the same? Justify your answer mathematically.