Logs!
Exponential EQ's
Word Problems
Solving Exponential EQ's
Solving Log EQ's
100

Simplify the expression: log28

What is 3?

100

Write the exponential equation 45= 1,024 in logarithmic form.

What is log41,024 = 5 ?

100
If there are initially 3000 bacteria in a culture, and the number of bacteria increase by 25% each hour, how many bacteria will there be in 5 hours? Round to the nearest whole number.
What is 9,155 bacteria?
100

Solve: 82x=8x+7

What is x=7?

100
Solve: log x = 3
What is 1000?
200

Write the equation log3729 = 6 in exponential form.

What is 36=729 ?

200

Write the exponential equation 271/3 = 3 in logarithmic form.

What is log273 = 1/3 ?

200

If there are initially 3000 bacteria in a culture, and the number of bacteria increase by 25% each hour, after how many whole hours will you reach approximately 5,850 bacteria?

What is 3 hours?

200

Solve: 25x-4=53x+1

What is x=-9 ?

200

log3x = 5

What is x = 243 ?

300

Write the equation log 1000 = 3 in exponential form.

What is 103=1000 ?

300

Write the exponential equation (1/2)-3=8 in logarithmic form.

What is log1/28 = -3

300

A $50 investment is placed into a college savings fund for a child earning 8% interest compounded quarterly. If the child was born the day the money was invested and won't have access to the account until they turn 18, how much money will they have available for college tuition?

What is $208.06?

300

Solve: e2x=ex+4

What is x=4?

300
Solve: ln x = 4 Round your answer to two decimal places.
What is x= 54.60 ?
400
What is the asymptote of the graph of f(x) = log(x - 1) ?
What is x=1 ?
400

Is the graph y= .7x increasing or decreasing, and is it a function?

What is decreasing and yes, a function?

400

A $240,000 loan is taken out in the year 2020 at a 2.5% interest rate compounded continuously. How much interest will the borrower have to pay back in 2035?

What is $109,197.94 ?

400

Solve: 3e3-x= 15 Round your answer to two decimal places.

What is x= 1.39 ?

400
Solve: 3 ln x - 7 = 4 Round your answer to two decimal places.
What is x= 39.12 ?
500
What is the asymptote of the graph of f(x)= log(x + 2) -1 ?
What is x= -2 ?
500

Simplify lne3x

What is 3x?

500

The value of a certain car in 2015 was $45,000. If the car depreciates at a rate of 3.5% annually, approximately how long, to the nearest whole year, will it take for the car to reach half of its original value?


Hint: What would half the original value be? Set the equation equal to that number and solve for t.

What is 19 years?

500

Solve: 102x+1 + 2 = 4 Round your answer to two decimal places.

What is x = -0.35 ?

500

Solve: ln60 - ln4 = ln(x2+2x)

Hint: two answers

What is x=-5 and x = 3 ?