#45 I can use exponential equations to predict future values

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

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? How would you calculate this?

• 800(1.29)⁶

• 800(0.29)⁶

• 800(0.71)⁶

Tags

CCSS.HSF.LE.A.4

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

• y = 15(35)^x

• y = 15(0.35)^x

• y = 15(1.35)^x

• y = 35(1.15)^x

Tags

CCSS.HSF.LE.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?

• 4000(1.25)⁴

• 4000(0.75)⁴

Tags

CCSS.HSF.BF.A.2

Which equation models the following situation:

There were 417 cell phones sold at an electronics store in January. Since then, cell phone sales at this store have increased at a rate of 3.75% per month. At this rate of growth, which function can be used to determine the monthly cell phone sales x months after January?

• f(x) = 417(3.75)^x

• f(x) = 417(0.0375)^x

• f(x) = 417(1.0375)^x

• f(x) = 417(1.375)^x

Tags

CCSS.HSF.LE.A.2

Which equation models the following situation:

An antibiotic is introduced into a colony of 12,000 bacteria during a laboratory experiment. The colony is decreasing by 14.9% per minute. Which function can be used to model the number of bacteria in the colony after x minutes?

• f(x) = 12000(14.9)^x

• f(x) = 12000( - 14.9)^x

• f(x) = 12000(1.149)^x

• f(x) = 12000(0.851)^x

Tags

CCSS.HSF.LE.A.2

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

• Growth
• Decay

Tags

CCSS.HSF-IF.C.8B

What is the starting value, for the function: f(x) = 300(1.16)^x?

• 300

• 1.16

Tags

CCSS.HSF.LE.B.5

Which equation models the following situation:

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year.

• y=5000(0.7)^x

• y=30(5000)^x

• y=5000(1.3)^x

• y=5000x^x

Tags

CCSS.HSF.LE.A.2

The population of Bloom Falls, Mass. (population 937) is slowly moving to a bigger city.
Every year the population drops by 4.5%. What is the population after 3 years?

• 1,069 people
• 894 people
• 816 people
• 854 people

Tags

CCSS.HSF-LE.A.1C