Growth or Decay?
Applying Exponential Equations
Exponential Growth/Decay Equations
Writing Exponential Functions
Exponent Rules
100

Does the following equation represent exponential growth or decay?

y=2^x

exponential growth

100

The population in the town of Huntersville is presently 38,300. The town grows at an annual rate of 1.2%. Find the population of the town after 9 years. Round to the nearest person.

38300(1.012)^9=42641

100

Consider the equation below. What is the initial value? 

y=250(1.2)^t

250

100

Write an exponential growth function to model the situation. A population of 422,000 increases by 12% each year. 

y=422000(1.12)^t

100

Simplify: 

6tv^0

6t

200

Does the following equation represent exponential growth or decay?

f(x)=100(0.5)^x

exponential decay
200

$1,200 is invested at an annual rate of 3.2%. How much money will the account have after 12 years? Round to the nearest cent.

1200(1.032)^12=$1751.21

200

Consider the equation below. What is the growth factor?

y=250(1.2)^t

1.2

200

Write an exponential growth function to model the situation. The population of Baconburg starts off at 20,000 and grows by 13% each year.

y=20000(1.13)^t

200

Simplify: 

4^2x^-2

4^2/x^2 or 16/x^2

300

Does the following equation represent exponential growth or decay?

y=100(1.4)^x

exponential growth

300

The population in the town of Deersburgh is presently 42,500. The town has been growing at a steady rate of 2.7%. What will the population of the town be in 5 years? Round to the nearest person. 

42500(1.027)^5=48556

300

Consider the equation below. What is the growth rate (as a percent)? 

y=250(1.2)^t

20%

300

The fish in a local lake are declining at an annual rate of 1.5%. Their current number is estimated at 2500. Write an equation to model the decreasing number of fish. 

y=2500(0.985)^t

300

Simplify: 

4x^-2g^3

(4g^3)/x^2

400

Does the following equation represent exponential growth or decay?

f(x)=7(0.94)^x

exponential decay

400

The value of a car was $22,000 when it was purchased. The car depreciates (decreases in value) at a rate of 19% per year. How much will the car be worth in 8 years? Round to the nearest cent.

22000(1-0.19)^8=$4076.64

400

Consider the equation below. What is the decay factor? 

y=9.8(0.35)^t

0.35

400

Write an exponential growth function to model the situation. Your starting annual salary of $64,000 increases by 3% each year.

y=64000(1.03)^t

400

Simplify: 

(4^-2x^-5y^-9z^-3)^0

1

500

Does the following equation represent exponential growth or decay?

f(x)=-350(1)^x

neither

500

The value of a stock when purchased is $10 a share. However, over the past 5 days the price went down at a constant rate of 4%. How much is the stock worth now? Round your answer to the nearest cent.

10(1-0.04)^5=$8.15

500

Consider the equation below. What is the decay rate (as a percent)? 

y=0.8(0.77)^t

23%

500

The squid in the magic forest lake were declining at an annual rate of 5.5%. Their current number is estimated at 50,000. Write an equation that represents this situation.

y=50000(0.945)^t

500

Simplify: 

(x^-2y^2)/(b^-4c^4)

(b^4y^2)/(x^2c^4)

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