# Questions on Algebra: Logarithm answered by real tutors!

Algebra ->  Algebra  -> Logarithm Solvers, Trainers and Word Problems -> Questions on Algebra: Logarithm answered by real tutors!      Log On

 Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations! Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!

 Algebra: Logarithm Solvers Lessons Answers archive Quiz In Depth

 Question 460601: Hey, I am studying for a test and I have a problem I'm stuck on. I know the solution to the problem but I'm not sure how to get there. Here's the problem: "How many years would it take an amount of oney to triple if it is invested at a rate of 5% compounded continuously?" To me that translates to A=Pe to the rt, so 3=e to the 0.05t, so ln 3=0.05t. THE SOLUTION is 20 ln 3. How does one get from ln 3 = 0.05t to 20 ln 3 = t? I hope I explained that clearly. Thanks for your help! Jessica Click here to see answer by lwsshak3(6505)

 Question 460653: simplify log base 2 of 8 - log base 2 of 4 Click here to see answer by jim_thompson5910(28595)

 Question 460232: if log3 equals t, then log 2700 can be expressed as what? Click here to see answer by lwsshak3(6505)

 Question 454172: how do i evaluate log(base 3)1/3 + log(base 5) square root 5 Click here to see answer by lwsshak3(6505)

 Question 460831: ```I am resubmitting this problem on logarithm, I entered yesterday, but got no response. Please help! Find f(x) such that h(x) = f∘g(x), where g(x)=8x+4, and ____ h(x)=Ö8x+4. Thank you``` Click here to see answer by Edwin McCravy(8909)

 Question 461053: I tried to solve this in all my calculators I have and all of them say unable to solve this type of logarithm even tho all of them have the (ln) function. Here is the equation 2ln(x-3)=ln(x+5)+ln4 When I input it in it asks if i'm solving for x or e.. not sure where the are getting the e from but anyway.. any help would be appreciated. Click here to see answer by ankor@dixie-net.com(15652)
 Question 461053: I tried to solve this in all my calculators I have and all of them say unable to solve this type of logarithm even tho all of them have the (ln) function. Here is the equation 2ln(x-3)=ln(x+5)+ln4 When I input it in it asks if i'm solving for x or e.. not sure where the are getting the e from but anyway.. any help would be appreciated. Click here to see answer by richard1234(5390)

 Question 461479: I'm having trouble with this question... and all my calculators give me the same answer which is none of the ones available. Solve the equation log(2+x)-log(x-5)=log 4 answers are A) 7/2 b 22/3 C 22/-3 D 0 Any help would be appreciated. Click here to see answer by graphmatics(170)

 Question 461481: One last one... Convert to exponential form.. again none of my calculators show the answers available. log 0.0000001=-7 A)-7^10=0.0000001 B) 0.0000001-7=10 C 10^-7=0.0000001 D)10 0.0000001=-7 any help would be appreciated. Click here to see answer by MathLover1(6634)

 Question 461526: Which application of exponential decay do you feel is the most important? Describe, give a model, and explain why? Click here to see answer by richard1234(5390)

 Question 461820: Hey, Quick question. I have the following problem: Using properties of logarithms, find the exact value of the expression: I know Change-of-Base formula, and that , but I don't know how to get to the answer, which is 18. A little explanation of the steps would be much appreciated! Thanks, Jessica Click here to see answer by asuar010(324)
 Question 461820: Hey, Quick question. I have the following problem: Using properties of logarithms, find the exact value of the expression: I know Change-of-Base formula, and that , but I don't know how to get to the answer, which is 18. A little explanation of the steps would be much appreciated! Thanks, Jessica Click here to see answer by solver91311(16885)

 Question 461926: Hello, I have a problem that asks the following: find where =2, =6, and =-2 I know the answer is -5; how to get there is beyond me. A little help would be amazing! Thanks, Jessica Click here to see answer by stanbon(57347)

 Question 462441: express the following as single logarithm. log a x + log a y - log a 5 thank you. Click here to see answer by math-vortex(472)

 Question 462919: Hello, I need help finding the vertical asymptote and the domain and range of a logarithm. log(x+8) I tried it myself and got (-8, infinity) for the domain and (-infinity, infinity) for the range. I also got x= -8 for the V.A. help? Click here to see answer by jim_thompson5910(28595)

 Question 463878: I have a question regarding radioactive decay. I am trying to solve the following problem: A certain amount of radioactive material decays according to the function A(t)=Ao e^-3t, where time is measured in hours. What is the half-life of the material in hours? So I know that I'm trying to find when A(t) equals half the original amount (Ao), but I'm not sure how to solve. I know that the solution is supposed to be ln(2)/3, just wondering how to get there. Thanks, Jessica Click here to see answer by stanbon(57347)

 Question 464240: What is the real value of x in the equation log345 - log35 = log7x? Click here to see answer by nerdybill(6959)

 Question 464260: A logarithm is an exponent. Explain, in your own words, why this is so. Justify your explanation with an example. Thank you! Click here to see answer by richard1234(5390)

 Question 464432: Prove that log 3=(log 2)+ (1/2)-(1/8)+(1/24)-(1/64)+....and so on. Click here to see answer by richard1234(5390)

 Question 464677: Find all real solutions (the fours after the logs are the bases of the logarithms): log4[x]+log4[x-63]=3 Click here to see answer by ewatrrr(10682)

 Question 465357: I have the following problem: " Use the properties of logarithms to find the exact value of the expression: 3 log 10 - log 25 - log 4 " I know that the answer is 1. Not sure on the properties that get us there. Thanks, Jessica Click here to see answer by ewatrrr(10682)

 Question 465374: I have a quick clarifying question: I solved a problem to where the two results are e^x= 1/3 or e^x= -2. I believe that you can't deal with the -2 because it's negative, but then my answer key is telling me that x= -ln 3. I guess this is because ln 1/3 is ln 1 - ln 3, but wouldn't that be -ln 2. I hope that makes sense to you, because I am confused. I guess I just need a little brush-up on some properties here. Thanks, Jessica Click here to see answer by richard1234(5390)

 Question 465437: Using the tables in the reference section, find the common logarithm of the number. Type the logarithm in mantissa + characteristic form. log 42.7 = ? + ? Click here to see answer by Edwin McCravy(8909)

 Question 465502: I need to solve the following: -=2 *I had to write this differently because of the formula plotting system (the second part is really e to the -x instead of 1/e^x). So I believe from here you subtract 2 from both sides and end up with everything equal to zero, and then you would let u=, so that you have u-(1/u)-2=0. Then I get confused as to how to solve this by using the quadratic formula, because I don't know what b=? . That is really all I am confused on, assuming I'm going about this the right way in the first place. I hope I've explained that well. Thanks! Jessica Click here to see answer by Alan3354(30993)

 Question 465529: please help me ive been staring st these questions for hours. Express as a single logarithm log 64 = x log 2 and also 10(r+1) = 2 Click here to see answer by richard1234(5390)