Evaluating Exponential Equations

Write an equation that models the following situation:

Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y = 6(0.14)^x

• y = 6(1 + 14)^x

• y = 6(1.14)^x

• y = 6(0.86)^x

Tags

CCSS.HSF.LE.A.2

You bought a Boston Whaler in 2004 for $12,500. The boat's value depreciates by 7% a year. How much is the boat worth in 2012?

• $11,625

• $6994.77

• $21,477

• $875

Tags

CCSS.HSF.BF.A.2

An adult takes 800 mg of ibuprofen. Each hour, the amount of ibuprofen in the person’s system decreases by about 29%. How much ibuprofen is left after 6 hours? 

• 101
• 102
• 103
• 104

Tags

CCSS.HSF.LE.A.4

Denise has $80 in a savings account that earns 10% annual interest.

To the nearest cent, how much will she have in 3 years?

• $106.48

• $26.48

• $8

• $104

Tags

CCSS.HSF.BF.A.2

The number of mosquitoes at the beginning of the summer was 4,000. The population of mosquitoes is expected to grow at a rate of 25% a month. How many mosquitoes will there be after 4 months?

• 9,765

• 9,006

• 5,433

• 5,000

Tags

CCSS.HSF.BF.A.2

Since January 1980, the population of the city of Brownville has grown according to the mathematical model y = 720,500(1.022)^x, where x is the number of years since January 1980. If the population continues to increase, what will it be in1995?

• 11,045,265

• 5,694,677

• 998,613

• 12,235

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y = 5000(0.7)^x

• y = 30(5000)^x

• y = 5000(1.3)^x

• y = 5000x^x

Tags

CCSS.HSF.LE.A.2

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x

• y = 15(1 + .35)^x

• y = 15(1 − .35)^x

• y = 35(1.15)^x

Tags

CCSS.HSF.LE.A.2

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

• y = 8(1 + 15,000)^x

• y = 15,000(1 + .08)^x

• y = 15,000(1 − .08)^x

• y = 15,000(0.08)^x

Tags

CCSS.HSF.LE.A.2

You have inherited land that was purchased for $30,000 in 1960. The value of the land increased by approximately 5% per year. What is the approximate value of the land in the year 2011?

• $361,223
• $310,500
• $150,000
• $280,500