Questions on Algebra: Logarithm answered by real tutors!

Tutors Answer Your Questions about logarithm (FREE)

Question 65665: Solve the equation ln(x+5)-ln(3)=ln(x-3).
Click here to see answer by venugopalramana(3286)

Question 65664: Ok I really need help.
"The amount A is an account after t years from an initial principle P invested at an annual rate r compounded continuously is given by A=Pe^rt where r is expressed as a decimal. How many years will it take an an initial investment of $1000 to grow to $1700 at the rate of 4.42% compunded continuously?"
Ok, so far I have
r=4.42/100=.0442
P=1000
t=?
A=(1000)e^(.0442) (?)
Do I have this right? what does "e" mean?
Click here to see answer by Earlsdon(6294)

Question 65661: Hi, the decibel level of sound is given by D=10log(I/10^-12), where I is the sound intensity measured in watts per square meter. Find the decibel level of a whisper at an intensity of 5.4x10^-10 watts per square meter. can anyone help?
Click here to see answer by Nate(3500)

Question 65623: Two earthquakes differ by 1.0 when measured on the richter scale. How would the seismographic readings differ at a distance of 100 kilometers from the epicenter? How do their intensities compare?
Click here to see answer by stanbon(57984)

Question 64603: 4. Solve for x: log v3 x + log v3 (x + 8) = 2
The v3 parts are supposed to be like the reverse of an exponent. They are at the bottom and not the top.

Click here to see answer by venugopalramana(3286)

Question 64601: Simplify: e^ln 72
Im guessing this is exponential form but im not sure
Click here to see answer by uma(370)

Question 64600: 1. Rewrite
in logarithmic form.
Any help would be much appreciated
Click here to see answer by ntnk(54)

Question 65738: I need help. The amount of radioactive tracer remaining after t days is given by A=A0e^-0.058t, where A0 is the starting amount at the beginning of the time period. How many days will it take for one half of the original amount to decay?
I've had trouble with this.
Click here to see answer by stanbon(57984)

Question 65737: Hi.
"The population P of a certain culture is expected tp be given by a model P=100e^rt where r is a constant to be determined and t is a number of days since the original population of 100 was established. I need to find the value of r if the population is expected to reach 200 in 3 days."
Click here to see answer by funmath(2925)

Question 65741: The amount of water remaining after t days is given by A=A0e^-0.18 where A0 is the starting amount at the beginning of the time period. How much should be acquired now to have 40 grams remaining after 3 days?
Click here to see answer by josmiceli(9819)

Question 65742: well the problem I have is with a table. I will do my best to explain it.
"For the information in the table providing values of f(x) and g(x), evaluate (f o g)^-1(3)."
x 1|2|3|4|5|
f(x) 5|3|5|1|2|
g(x) 4|5|1|3|2|

x is over f(x) and g(x)
Thanks!

Click here to see answer by stanbon(57984)

Question 64602: 3. Use the properties of logarithms to expand completely.
log v3<--(supposed to be at the bottom of the log, like a reverse exponent)ab/c^2
Click here to see answer by Edwin McCravy(8999)

Question 64621: Solve, and express your answer in exact form 3^x = 4^(l-x)
Click here to see answer by ankor@dixie-net.com(15747)

Question 66005: I have two questions Im really stuck on
The first question is:
4^2x = 2^x(x-2)
And the second is:
2^x+3 = 3^x-1
If you could help me out with both of these questions that would be greatly appreciated.
Thank you
Click here to see answer by josmiceli(9819)

Question 66076: log2x+log(x+1)=log(log1000)
log7-log(4x+5)+log(2x-3)=0
logx^5=(logx)^5
3^92x+1)=4^(3-x)
Click here to see answer by Nate(3500)

Question 66292: Can someone think of a logarithmic function that we encounter in our work or in our personal life?
Click here to see answer by stanbon(57984)

Question 66461: I have two questions that I am confused on Please help!
1. Solve for x: log10 9 = log10 x - log10 3
2. Write as the sum or difference of x, y, and z: log6 {[2y^4 * √x] / a^4}

Click here to see answer by ankor@dixie-net.com(15747)

Question 66703: Reduce the following to a single logarithm
2log2-3log4+log6
Click here to see answer by stanbon(57984)

Question 66704: Can you please help me solve the following single logarithm
2log2-3log4+log6
Click here to see answer by Nate(3500)

Question 64622: Solve, and express you answer in exact form: log(x) + ln(x) = 1
Click here to see answer by rapaljer(4667)

Question 64347: Can you help me with these log problems? solve with calculator to the fourth place
Thanks
14.)log 0.0332
15.)ln 40,257
16.) log x-2.0832
17.) ln x = -1.1577
Click here to see answer by rapaljer(4667)

Question 67013: Which is greater : log 3 to the base 2 or log 5 to the base 2.5
Click here to see answer by stanbon(57984)

Question 67011: If x = 1+ log a bc, y=1+log b ca and z=1+log c ab, prove that xyz = xy+yz+zx.
Click here to see answer by tanimachatterjee(60)

Question 67014: If a,b,c are distinct positive numbers each different from 1 such that {(log a to the base b)(log a to the base c) – log a to the base a} + {(log b to the base a)(log b to the base c) – log b to the b} + {(log c to the base a)(log c to the base b) – log c to the base c} = 0 , then prove that abc = 1
Click here to see answer by venugopalramana(3286)

Question 67311: Please help to simplify
solve for x :
log5(x + 3) + log5 4 = log5 36

Click here to see answer by Nate(3500)

Question 67311: Please help to simplify
solve for x :
log5(x + 3) + log5 4 = log5 36

Click here to see answer by raghu_pratoori(2)

Question 67505: Given Loga4= 1.386, Loga5=1.609, and Loga6= 1.792, find Loga100
Click here to see answer by stanbon(57984)

Question 67830: using logarithms solve index is 5, radical sign over 125/0.55
Click here to see answer by stanbon(57984)

Question 67952: express as a single logarithm
5logN-3logN^4 (the last part meens exponent 4)
Click here to see answer by stanbon(57984)

Question 67954: solve the equation with logs
(9/16)^x=3/4
Click here to see answer by ankor@dixie-net.com(15747)

Question 68062: How large do you need to make x so that e^(-x/9) that is less than 0.1?

I tried inputting values for x and I came up with 21 as the value for x.
Click here to see answer by stanbon(57984)

Question 68098:
Please help.I having trouble with this problem.
Logarithms:
a) Using a calculator, find log 1000 where log means log to the base of 10.
Answer:

b) Most calculators have 2 different logs on them: log, which is base 10, and ln, which is base e. In computer science, digital computers are based on the binary numbering system which means that there are only 2 numbers available to the computer, 0 and 1. When a computer scientist needs a logarithm, he needs a log to base 2 which is not on any calculator. To find the log of a number to any base, we can use a conversion formula as shown here:

Using this formula, find . Round your answer to the hundredth's place.
Answer:
Show work in this space.

Click here to see answer by Edwin McCravy(8999)

Question 68180: 5) Logarithms:
a) Using a calculator, find log 1000 where log means log to the base of 10.
Answer:

b) Most calculators have 2 different logs on them: log, which is base 10, and ln, which is base e. In computer science, digital computers are based on the binary numbering system which means that there are only 2 numbers available to the computer, 0 and 1. When a computer scientist needs a logarithm, he needs a log to base 2 which is not on any calculator. To find the log of a number to any base, we can use a conversion formula as shown here:

Using this formula, find . Round your answer to the hundredth's place.
Answer:
Show work in this space.

Click here to see answer by stanbon(57984)

Question 68507: I feel really dumb asking this question but here it goes anyways.
Evaluate: log(base 3) 105
Click here to see answer by stanbon(57984)

Question 68563: with the exponet of 5 radical sign over 125/.55 show process using logarithms (sorry index of 5)
Click here to see answer by Edwin McCravy(8999)

Question 68578: Please help to solve
log3(x+7) + log3 2 = log3 20
Click here to see answer by Nate(3500)

Question 67864: Find the pH if H+ = 2.68 * 10^-3 mole per liter. (pH = - logH+ or 10^-pH = H+)
Click here to see answer by Nate(3500)

Question 69291: log25x=1/2
find x in decimal
Click here to see answer by Earlsdon(6294)

Question 69297: Explain the difference between a logarithm of a product and the product of a logarithm, Please given examples of the difference
Click here to see answer by Nate(3500)

Question 69434: 1.the exact value of log4[log3(log28)]
2. If log3 = A and log7 = B, find (log base of 7) 9 in terms of A and B?
3. Exponential functions and logarithmic functions are inverse functions. It is because of this that it would make sense that they have some similar properties. Identify which property of exponents is similar to logAB = logA + logB and which is similar to logA/B = logA – logB. Explain how they are similar.
Click here to see answer by stanbon(57984)

Question 69441: Find the exact value of log base of 4[log base of 3(log base of 2)8)] without using a calculator, explaining all steps.

Write e^ln8x^5 - ^ln2x^2 as a single term that does not contain a logarithm. Show and explain work
Click here to see answer by stanbon(57984)

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