8.2 C Exponential Equations from Word Problems

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. Write an equation.

•  $y=4000\left(1.25\right)^x$  

•  $y=4000\left(.25\right)^x$  

•  $y=4000\left(25\right)x$  

•  $y=4000\left(.75\right)^x$  

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(0.35)^x

• y = 15(1.35)^x

• y = 35(1.15)^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%. What equation could be used to represent this?

• $y=800\left(.29\right)^x$

• $y=800\left(.71\right)^x$

• $y=800\left(29\right)^x$

• $y=800\left(1.29\right)^x$

Tags

CCSS.HSF.LE.A.2

Your cousin a Boston Whaler in 2014 for $12,500. The boat's value depreciates by 7% a year.

• $y=7\left(12500\right)^x$

• $y=12500\left(7\right)^x$

• $y=12500\left(.93\right)^x$

• $y=12500\left(1.07\right)^x$

Tags

CCSS.HSF.LE.A.2

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What percent did the population increase each year?

• 4%

• It doesn't say

• 1.04%

• 104%

Tags

CCSS.HSF-LE.A.1C

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What was the population in 1990?

• 0 people

• It doesn't say

• 6191 people

• 104 people

Tags

CCSS.HSF-LE.A.1C

In an exponential function, what does the 'a' represent?

• Slope

• Rate of Change

• y-intercept

• Common Ratio

Tags

CCSS.HSF.LE.B.5

Identify the y-intercept (initial value) in the function f(x)=13(.27)^x

• (.27)^x

• .27

• 13

• 3.51

Tags

CCSS.HSF.LE.B.5

What type of function is  $y=7\left(\frac{5}{4}\right)^x$  ?

• Exponential Growth

• Exponential Decay

• Linear

• None of theses

Tags

CCSS.HSF-IF.C.8B

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