How do I Solve a Basic Logarithm Problem?

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In summary, to solve for x, first rewrite the logarithmic equation as an exponential equation by setting the bases equal to each other. Then, solve for x by isolating it on one side of the equation using algebraic operations. In this case, x is equal to 4 and 5, respectively.
  • #1
susanto3311
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hi guys..

i need help to solve logarithm problem

how to find x?

thanks any help..
 

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  • #2
susanto said:
[tex]\text{Solve for }x:\;^{3x-2}\log 100 \:=\:^2\log 4.[/tex]

I've never seen logarithms written like that . . .

[tex]\begin{array}{ccc}\text{We have:} & \log_{3x-2}100 \:=\:\log_24 \\
& \log_{3x-2}100 \:=\:2 \\
& (3x-2)^2 \:=\:100 \\
& 3x-2 \:=\:10 \\
& 3x\:=\:12 \\
& x \:=\:4
\end{array}[/tex]

 
  • #3
susanto3311 said:
hi guys..

i need help to solve logarithm problem

how to find x?

thanks any help..
Is this supposed to be \(\displaystyle \text{log}_{100}(3x - 2) = \text{log}_4 (2)\)?

-Dan
 
  • #4
hi...

what is finally for x?
 
  • #5
hi soroban...
thank, but how about this...

[tex]\begin{array}{ccc}\text{We have:} & \log_{2x-5}125 \:=\:\log_28 \\

- - - Updated - - -

soroban said:

I've never seen logarithms written like that . . .

[tex]\begin{array}{ccc}\text{We have:} & \log_{3x-2}100 \:=\:\log_24 \\
& \log_{3x-2}100 \:=\:2 \\
& (3x-2)^2 \:=\:100 \\
& 3x-2 \:=\:10 \\
& 3x\:=\:12 \\
& x \:=\:4
\end{array}[/tex]


hi soroban...
 

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  • #6
susanto3311 said:
[tex]\log_{2x-5}125 \:=\:\log_28 [/tex]

[tex]\begin{array}{cc}\log_{2x-5}125 \:=\: \log_28 \\
\log_{2x-5}125 \:=\:3 \\
(2x-5)^3 \:=\:125 \\
2x-5 \:=\: 5 \\
2x \:=\: 10 \\
x \:=\:5
\end{array}[/tex]
- - Updated - - -
 

Related to How do I Solve a Basic Logarithm Problem?

What is a logarithm?

A logarithm is the inverse function of exponentiation. It is used to solve exponential equations and is defined as the power to which a base number must be raised to equal a given number.

What is the base of a logarithm?

The base of a logarithm is the number being raised to a power. For example, in the logarithm "log28", the base is 2.

How do you solve a basic logarithm problem?

To solve a basic logarithm problem, you can use the logarithmic identity logbx = y if and only if by = x. This means that you can rewrite a logarithm as an exponential equation and solve for the unknown variable.

What is the difference between logarithmic and exponential functions?

The main difference between logarithmic and exponential functions is the operations they perform. Logarithmic functions "undo" the operation of an exponential function, while exponential functions "undo" the operation of a logarithmic function.

Can you have a negative number as the base of a logarithm?

No, the base of a logarithm must be a positive number. This is because a negative base would result in an undefined or imaginary answer.

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