Exponential Evaluate

• 125

• 15625

• 25

• 30

Answer explanation

Follow order of operations. Exponents first.

f(2) indicates that x = 2

The exponent is 3x, so 3*2 = 6

The exponent is 6.

5⁶ or 5^6

An investment of $8000 in a certain Certificate of Deposit (CD) doubles in value every seven years. The function that models the growth of this investment is , where x is the number of years. If the investor does not withdraw any money from this CD, how much money will be available for withdrawal after 28 years?

• $128,000

• $1,024,000

• $112,000

• $2,147,483,648,000

Answer explanation

x=28. So, the exponent is 28/7 = 4. The exponent is 4.

2⁴ = 2^4 = 16. Multiply by 8000.

A new car cost $15,000 to build in 2010. The company’s financial analysts expect costs to rise by 6% per year . The cost to build the car can be modeled by the function f (t) = 15,000 (1.06)^{t} , where t is the number of years after 2010. How much will it cost the company to build the car in 2017?

• $22,554.45

• $19,678.32

• $23,907.72

• 45,678.91

Answer explanation

t is the number of years after 2010. So, t=2017-2010

=7. So, the exponent is 7.

1.06⁷ = 1.06^7 . Multiply by 15000.

• 2835

• 105

• 420

• 121550625

Answer explanation

x is the 4.

So, the exponent is 4.

3⁴ = 3^4 . Multiply by 35.

Linear, exponential, or neither?

y = 4(3)^x

• Linear

• Exponential

• Neither

Linear, exponential, or neither?

Amount triples each year

• Linear

• Exponential

• Neither

There are 800 students at Western Middle. The population increases by 3% each year.

• Linear

• Exponential

• Neither

Evaluate the function for the given value:

f (x) = 5^x for f(4)

• 20

• 625

• 125

• 25

An investment of $8000 in a certain Certificate of Deposit (CD) doubles in value every seven years. The function that models the growth of this investment is f (x) = 8000(2)^x, where x is the number of 7 year periods. If the investor does not withdraw any money from this CD, how much money will be available for withdrawal after 28 years?

• $128,000

• $1,024,000

• $2,147,483,648,000

• $112,000

A population of amoebas in a petri dish will triple in size every 20 minutes. At the start of an experiment the population is 800. Write a function to model this relationship with y representing the total population, and x as the number of 20 minute periods.  How many amoebas are in the petri dish after 3 hours?

• 15,746,400

• 216,000

• 27,894,275,208,000

• 67.893