Questions on Algebra: Logarithm answered by real tutors!

Tutors Answer Your Questions about logarithm (FREE)

Question 112946: Help! I need help with two problems on my pre-test for my finals.
1. Write log 125 base 5 = 3 in exponential form
2. Simplify:Log 6 base 6

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Question 112962: What is the Evalution of Logarithm of 16?
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Question 113161: Phosphorous-32 is used to mark cells in biological experiments. If phosphorous-32 has a continuous daily decay rate of 4.85%, what is the half-life?
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Question 113219: How do you solve this exactly?
log(x+20)-log(x+2)=log x
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Question 113440: I need help with 2 problems using my new TI-84 Plus:
1.find x: log x=3.8893
The answer I got was:.5898714436 Is this correct?
2.find x: log x = -1.5003
I enter LOG(-1.5003) enter and I get an error:syntax message Help!!
Click here to see answer by edjones(7569)

Question 113487: simplify log1 -3 log2 + log16
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Question 113501: How do I solve this equation. If needed, I can round to the nearest three decimal places.

1nx=2
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Question 113499: How can I write the expression 2.1n x-1n y+3. 1n z as a single lograithm. The periods after the 2 and 3 stands for the (times) sign not periods.

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Question 113509: How do I write the expression 2. In x-1n y+3 . 1n z as a single logarithm?
(note) the (.) after the 2 and 3 represent the times sign.
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Question 113537: I'm a tutor, but I have a question which I can't answer myself, other tutors please help.
How do you solve ?
For example
which is We all know that 4 satisfies the equation, but how do you actually solve this kind of problems? Is there only one possible solution?
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Question 113610: log3 (x+2) + log3 (x-2) = 1
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Question 113687: Usinng this formula : logb2=0.310, logb3=0.4771, and logb5=0.6990 slove
log5 135 and rounded 4 decimals
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Question 113802: Solve for x:
=
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Question 113802: Solve for x:
=
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Question 114000: expand and simplify (Do Not find approximations): 1n(e/x)
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Question 114008: simplify: log (1000)
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Question 114080: Use the calculator to find the common logarithm: log 4,700
Choose 1 answer:
a.8.4596
b.3.6721
c.4.6739
d.-1.3582
Click here to see answer by stanbon(57387)

Question 114082: Please help w/pre-test for final.
Find f^-1 (x), if it exists, for f(x) = 6x+5
Find the total amount of money in an account if $8000 was deposited 6 years ago at 2% interest compounded semi-annually.
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Question 114085: Evaluate the logarithm
log (7, 1/49)

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Question 114089: A deposit of $1000 is made into a fund with an annual interest rate of 10%. Find the time(in years) necessary for the investment to double if the interest is compounded continuously.
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Question 114090: If ln 4=1.3863, ln 3=1.0986, and lf 5=1.6094, find ln 3/20?
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Question 114077: Will donate. Please help solve two problems.
1.Use the properties of logarithms to write the following expression as a single logarithm:

2.Use the properties of logarithms to expand the expression as much as possible:

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Question 114114: Solve for x: log(x - 5) + log 4 = 2.
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Question 114128: Write as a single logarithm and simplify (no decimal approximations): 2 log 6 + log x - log 3.
Click here to see answer by edjones(7569)

Question 114124: Solve for x: 3^x = 4
Select an answer below
a.log 4/3
b.log 4/3
c.log 4-log 3
d.ln 4/ln 3
Solve for x: 9^x+2 = 27
Select an answer below
a.1
b.2/3
c.-1/2
d.-2

Click here to see answer by edjones(7569)

Question 114135: I am having problems with this solution:
Solve for x: log(x - 5) + log 4 = 2
Please help. Thanks
-Ryan
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Question 114126: Find the domain of the function f(x) = ln(12x - 48).

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Question 114159: Need Help, Please!
Use the product,quotient, and power rules of logarithms to rewrite the expression as a single logarithm. Assume that all variables represent positive real numbers.
1/2 log(2,x^4) + 1/4 log(2,x^4) - 1/6 log(2,x)

Thank you!
Click here to see answer by stanbon(57387)

Question 114092: about this question..
log (7, 1/49)
log with a base of 7

Evaluate the logarithm..
log(7, 1/49)
or if this is better
log7 1/49
(7 is the base)
would it
be 2 or -2??
because log (7, (1/7)^2
or log7 (1/7)^2
the 7's would cancel leaving 2
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Question 114395: Solve: 4^w=1/64
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Question 114400: Solve: 3^(x^2+4x) = 1/27
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Question 114399: Solve: log(subscript 6)x + log(subscript 6)(x-5) = 2
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Question 114659: I have tried everything and I just don't understand this problem.
Here is the problem
=

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Question 114659: I have tried everything and I just don't understand this problem.
Here is the problem
=

Click here to see answer by Edwin McCravy(8909)

Question 114690: How to solve for x in the equation
log(sub 5)(x+4) + log(sub 5)(x) = 2
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Question 114803: Solve the following:
log(4x+9)=1
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Question 115028: I need help Soloving this equation! Not sure How to really Start the problem,
ln(x-2)+ln(2x-3)=2lnx

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Question 115041: I need help solving this equation:
2(2^2t-5)-4=10 and it says to give approximate answer.. im not real sure how to even start it
Thanks
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Question 115033: I need help solving this word problem:
The debt on a certain credit card follows the function d=9000*1.015^t where d = debt in $ and t= time in months.
A)How much debt will be owed in t=6 months?
B)How long will it take for debt to exceed $15,000?
I think i have A) here is what i did on it:
d=9000*1.015^6
d=$9,840.99
And i couldnt finish b part but here is where i got:
$15,000=9,000*1.015^t
6,000=1.015^t
I just dont understand how to get the t down from an exponent and finsih it for t!

Any help is greatly appreciated THANKS!
Click here to see answer by scott8148(6628)

Question 115120: 2^x - 6(2^-x) = 6
This problem is from Schaum's Outlines - Precalculus, chapter 19 page 180.
That book doesn't provide many examples (let alone good ones) so, while I can solve a similar one (or that same one if I plug = 1 instead of = 6), I don't know how to solve this one.
It should be ??? = 3 and then we work it out, but unless I'm muliplying 2^x by 1, I don't know what u will equal. So I can't find the value for x.
(2^x)^2 - 6 = 6.2x
u^2 = (2^x)^2 u = ???

Click here to see answer by jim_thompson5910(28598)

Question 115137: Solve the following algebraically: e^x-6e^-x=1; this is what I have thus far.
e^x(e^x-6e^-x)=e^x(1)
e^2x-6=e^x
e^2x-e^x-6=0
then use a quadratic equation to solve:
-(-1) +-square root (-1)^2-4(1)(-6)/2(1)
1+-square root 1+24/2
1+-square root 25/2
1+-5/2 = 1.0986
Is this correct?
Click here to see answer by jim_thompson5910(28598)

Question 115200: I am having trouble with this toic can someone please help me.
Solve logarithmic equation
log x + log(x+9) = 1
Thank you inadvance for your help.
Click here to see answer by scott8148(6628)

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