- #1
scientifico
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Homework Statement
3x + 3x+1 = 4x
Can I do this ?
Log 3x + Log 3x+1 = Log4x
thanks
Solve Logarithm Equation: 3x + 3x+1 = 4x
- Thread starter scientifico
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In summary, the conversation discusses the validity of a logarithmic law and the process of solving equations involving logarithms.
3x + 3x+1 = 4x
Can I do this ?
Log 3x + Log 3x+1 = Log4x
thanks
- #2
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No, you can't. The law
[tex]\log(a+b)=\log(a)+\log(b)[/tex]
is not valid.
[tex]\log(a+b)=\log(a)+\log(b)[/tex]
is not valid.
- #3
Dick
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scientifico said:
Absolutely not. log(3^x)+log(3^(x+1))=log(3^x*3^(x+1)), not log(3^x+3^(x+1)).
- #4
scientifico
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How can I solve my equation ?
- #5
tiny-tim
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hi scientifico! 
no!
hint: factorise 3x + 3x+1
scientifico said:
no!
log(a + b) is not loga + logb !
hint: factorise 3x + 3x+1
- #6
Dick
Science Advisor
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scientifico said:
3^(x+1)=3*3^x. Try using that.
- #7
scientifico
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Thanks I solved.
- #8
scientifico
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3(1-3^x) < 5^x(1-3^x)
must I impose 1-3^x > 0 and 1-3^x < 0 ?
must I impose 1-3^x > 0 and 1-3^x < 0 ?
- #9
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scientifico said:
Please post new questions in a separate thread.
FAQ: Solve Logarithm Equation: 3x + 3x+1 = 4x
1. What is a logarithm equation?
A logarithm equation is an equation that involves the use of logarithms. Logarithms are mathematical functions that are the inverse of exponential functions. They are used to solve for unknown variables that are in the exponent.
2. How do you solve a logarithm equation?
To solve a logarithm equation, you need to isolate the logarithm term on one side of the equation and the non-logarithmic terms on the other side. Then, you can use the properties of logarithms to simplify the equation and solve for the unknown variable.
3. What are the properties of logarithms?
The properties of logarithms include the product property, quotient property, power property, and change of base property. These properties allow us to manipulate logarithmic expressions and equations to make them easier to solve.
4. Can you give an example of solving a logarithm equation?
For example, let's say we have the equation log2(x+3) = 2. To solve this, we can rewrite it using the power property as 22 = x+3. Then, we can subtract 3 from both sides to get x = 1. Therefore, the solution to the equation is x = 1.
5. How do you know if your solution to a logarithm equation is correct?
You can check your solution by plugging it back into the original equation. If it satisfies the equation, then it is the correct solution. In our previous example, we can plug in x = 1 to get log2(1+3) = 2, which simplifies to 2 = 2, showing that our solution is correct.