advertisement

Algebra: Exponential Unit Review Packet 1. Name___________________________________ p 1000 1.25 t A colony of bacteria grows according to the equation: where p is the population after t hours. What will the population be in 4 hours? What was the population 4 hours ago? What is the rate of growth for this colony of bacteria? 2. Match each description with its graph: ________i. Linear increase (growth) ________ii. Linear decrease (decay) ________iii. Exponential increase (growth) ________iv. Exponential decrease (decay) ________v. Quadratic A D E C B 3. A car costs $15,000 and loses 18% of its value every year. Write an equation expressing the value of the car in t years. How much will the car be worth in 5 years? 4.) You put $4000 in an account that earns 3.5% interest each year. a.) Write an equation. b.) How much money will you have in 10 years? 5.) There are currently 25000 people in a town that has been growing by 12% each year. a.) Write an equation. b.) How many people will there be in 2022? c.) How many people were there in 2000? 6.) Trumaine had $285, but he lost $15 every day until he had no money left. For how many days did he lose money? 7.) There are currently 3200 students at ETHS, but the population is decreasing by 6% per year. a.) Write an equation. b.) How many students will there be in 20 years? 8. Change to scientific notation: a. 16 billion 9. b. .000062 Once Whitney was using a friend’s calculator. She correctly found this answer on the machine’s screen: 4.628345 E 6 Is this answer between 4 and 5? ___________ If “NO,” then name two numbers that her answer falls between: 10. A sad teacher I know has an investment portfolio that has lost money for the last 3 years. When it started, the value was about $30,000. It has lost 6% per year during that time. What is the value of this investment today? 11. The amount of lead in a person’s body falls by the same percentage rate each day after that person has swallowed the lead contaminant. Which graph below shows how the amount of lead changes over time? ____________ A lead B lead time C time lead lead time time F E D lead lead time Which graph above most closely matches the equation: y 2x 40 ? ____________ time