Exponential Growth and Decay Equations

Some banks charge a fee for a savings account that is left inactive for an extended period of time. The equation y = 5000(0.98)^x represents the amount remaining, y, of one account that was left inactive for a period of x years. What does the number 5000 represent in this situation?

• fee charged for an inactive account

• percent of money in the account after x years

• amount of money in the account initially

• amount of money in the account after x years

Tags

CCSS.HSF.LE.B.5

The function f(x) = 12,500(0.89)^x models the value of a car x years after its purchase. Which statement is true about the value of the car?

• The value is decreasing at a rate of 11% per year.

• The value is decreasing at a rate of 89% per year.

• The value is increasing at a rate of 11% per year.

• The value is increasing at a rate of 89% per year.

Tags

CCSS.HSF-IF.C.8B

Genevieve deposited $400 into her bank account. The equation A(t) = 400(1.07)^x can be used to calculate the value of her money after t years. What is the annual interest rate she is earning on her deposit?

• 0.07%

• 1.07%

• 7%

• 10%

Tags

CCSS.HSF-LE.A.1C

The function f(x) = 250(1.12)^x models the number of students at a school x years after it opened. By what rate is the number of students increasing each year?

• 0.12%

• 0.88%

• 12%

• 88%

Tags

CCSS.HSF-IF.C.8B

The function f(x) = 24500(0.84)^x models the population of a town t years after 2008. What rate is the population of the town decreasing each year?

• 24.5%

• 75.5%

• 16%

• 84%

Tags

CCSS.HSF-IF.C.8B

A population of 2200 beetles is too large to sustain and decreases in population each month at a rate of 5%. How would you write your decay factor, b?

• -5

• -.05

• .95

• .05

Tags

CCSS.HSF-LE.A.1C

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the decay rate?

• ^0.08

• ^1.08

• 0.92

• 8%

Tags

CCSS.HSF-LE.A.1C

Suppose you deposit $3000 in a savings account that pays interest at an annual rate of 4%. What is the growth factor?

• .96

• 1.4

• 1.04

• $3000

Tags

CCSS.HSF-IF.C.8B

Is this equation exponential growth, decay, or neither?

• Exponential Growth

• Exponential Decay

• Neither

Tags

CCSS.HSF-IF.C.8B

Is this exponential growth or decay?

• Growth

• Decay

Tags

CCSS.HSF-IF.C.8B