Unit 5 Exam Practice: Exponential Functions

Jill invests $400 in a savings bond. The value of the bond, V(x), in hundreds of dollars after x years is illustrated in the table.

a. State whether this situation is growing or decaying.

1. b. Write an equation that illustrates the approximate value of the bond in hundreds of dollars over time in years.

Tags

CCSS.HSF.LE.A.2

The number of bacteria in a lab can be modeled by P(t) = 300(2)^4t, where t is the number of hours. Which expression is equivalent to P(t)?

• 300 • 8^t

• 300 • 16^t

• 300^t • 2⁴

• 300^2t • 2^2t

Tags

CCSS.HSF-IF.C.8B

A movie theater recorded the number of tickets sold daily for a popular movie during the month of June. The box-and-whisker plot shown below represents the data for the number of tickets sold, in hundreds.

Which conclusion can be made using this plot?

• The second quartile is 600.

• The mean of the attendance is 400.

• The range of the attendance is 300 to 600.

• Twenty-five percent of the attendance is between 300 and 400.

Tags

CCSS.6.SP.B.4

CCSS.HSS.ID.A.1

If point (k, -5) lies on the line whose equation is 3x + y = 7, then the value of k is: ?

A country has a population of 600,000. Due to a lack of jobs and slow economic growth, the population is decreasing by 8%. Write a function that shows this percent change in population t decades after the year 2000.

Tags

CCSS.HSF.LE.A.2

The solution of an equation with two variables, x and y, is

• The set of all x values that make y = 0.

• The set of all y values that make x = 0.

• The set of all ordered pairs, (x,y), that make the equation true.

• The set of all ordered pairs, (x,y), where the graph of the equation crosses the y-axis.

At Ron's Rental, a person can rent a big-screen television for $10 a month plus a one-time "wear-and-tear" fee of $100. At Josie's Rental, the charge is $20 a month and an additional charge of $20 for delivery with no "wear-and-tear" fee.

a. If c equals the cost, write one equation representing the cost of the rental for m months at Ron's Rental and one equation representing the cost of the rental for m months at Josie's Rental.

b. Enter the graphs in the graphing calculator and determine which month Josie's cost will equal Ron's cost.

Tags

CCSS.HSF.LE.B.5

When a child is born, her grandfather decided to put $100 in an account that earns 2.8% interest. The child can withdraw money starting at 18 years old. She decides she's not going to withdraw the money however, until she's 30. How much more money will she earn, to the nearest cent, by keeping it in the account for 12 more years?

The dollar value of a car is a function, f, of the number of years, t, since the car was purchased in 2020. The function is defined by the equation f(t) = 12,000 • (3/4)^t.

a. How much was the car worth when it was purchased? Explain how you know.

b. Approximately how much will the car be worth in 2025? Show your work or reasoning.

Tags

CCSS.HSF.LE.B.5