Finding the Unknown Variable in a System of Linear Equations

  • Thread starter chwala
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    Logarithm
In summary, the problem is to find log_{xz}m given that log_{xy}m = 9, log_{yz}m = 18, and log_{xyz}m = 8, where x, y, z, and m are all greater than 1. The solution involves transforming the equations into a set of linear equations and solving for a such that ax + az = 1.
  • #1
chwala
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Homework Statement
let ##x,y,z>1##, and ##m>1## so that ##log_{xy}m=9##

##log_{yz}m=18##

##log_{xyz}m=8##

find ##log_{xz}m##
Relevant Equations
logarithms
1593317158084.png


this is my working...
 
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  • #2
chwala said:
Homework Statement:: let ##x,y,z>1##, and ##m>1## so that ##log_{xy}m=9##

##log_{yz}m=18##

##log_{xyz}m=8##

find ##log_{xz}##
Relevant Equations:: logarithms

View attachment 265398

this is my working...
find ##log_{xz}##
The problem statement is incomplete. ##\log_{xy}## of what?
This is like asking what is ##\sqrt{}##?
 
  • #3
sorry let me amend the question...
 
  • #4
find ##log_{xz}m##...i checked with my colleague, my solution is correct, i would be looking at probably an alternative approach. thanks
 
  • #5
chwala said:
find ##log_{xz}m##...i checked with my colleague, my solution is correct, i would be looking at probably an alternative approach. thanks
You can transform this into a set of linear equations:
$$9x + 9y = 1, \ \ \ 18y + 18z = 1, \ \ \ 8x + 8y + 8z = 1$$
And you want to find ##a## such that:
$$ax + az = 1$$
 
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  • #6
PeroK said:
You can transform this into a set of linear equations:
$$9x + 9y = 1, \ \ \ 18y + 18z = 1, \ \ \ 8x + 8y + 8z = 1$$
And you want to find ##a## such that:
$$ax + az = 1$$

let me check this out...
 

What is a logarithm?

A logarithm is the inverse operation of exponentiation. It helps us solve problems involving exponential growth or decay.

How do I solve a logarithm problem?

To solve a logarithm problem, you need to use the properties of logarithms and algebraic manipulation. Start by rewriting the logarithmic equation in exponential form, then use the properties of logarithms to simplify the equation. Finally, solve for the unknown variable.

What are the properties of logarithms?

The three main properties of logarithms are:

  • Product property: logb(xy) = logb(x) + logb(y)
  • Quotient property: logb(x/y) = logb(x) - logb(y)
  • Power property: logb(xn) = n * logb(x)

What are common mistakes when solving logarithm problems?

Some common mistakes when solving logarithm problems include:

  • Forgetting to use the properties of logarithms
  • Mixing up the base of the logarithm
  • Not simplifying the equation enough before solving for the variable
  • Forgetting to check for extraneous solutions

Do I need a calculator to solve logarithm problems?

While a calculator can be helpful, it is not always necessary to solve logarithm problems. With the proper understanding of logarithms and their properties, you can solve many logarithm problems without a calculator. However, for more complex problems, a calculator may be useful.

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