Exponential Growth and Decay Factors and Rates

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

What type of function does the equation y = 2^x represent?

• Exponential Growth

• Exponential Decay

• Linear

• Quadratic

Does the following equation model growth or decay? y = 500(.30)^x + 7

• Growth by 30%

• Growth by 70%

• Decay by 30%

• Decay by 70%

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

• y=8(15,000)^x

• y=15,000(1.08)^x

• y=15,000(0.92)^x

• y=15,000(0.08)^x

What is the percent (%) of increaase or decrease in the following equation? f(x) = 250 (0.95)^x

• Decrease by 95%

• Increase by 5%

• Decrease by 5%

• Increase by 95%

Does the following represent growth or decay? y = 1/2(1.25)^x + 2

• Growth by 25%

• Growth by 75%

• Decay by 25%

• Decay by 75%

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

• ^.08

• ^1.08

• .92

• 8

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(0.35)^x

• y = 35(1.15)^x

Classify the model as Exponential GROWTH or DECAY.
A=1200(.85)⁶

• Growth

• Decay

Classify the model as Exponential GROWTH or DECAY.
A=10(1.01)³

• Growth

• Decay