logarithmic

[latresa31s]

can someone help me find x for this problem. I am not sure of what and how to use the property to solve.

log(base10) 25 = log(base10) x – log(base10) 5

 

[mmm4444bot]

Definition of a Logarithm

Hello latresa31s:

Isolate the term containing the variable on one side of the equals sign.

log(x) = log(25) + log(5)

This equation -- by the definition of the log[base 10] function -- tells us that:

If we raise 10 to the power of log(25) + log(5), we will get x.

So, use your calculator to do it. You should find that x = 125.

~ Mark

 

[Gene]

Or you can remember log(a)+log(b)=log(a*b)
log(x)=log(125)
x=125 without a calcultor

 

[soroban]

Hello, latresa31s!

\(\displaystyle \log_{10}(25) \;= \;\log_{10}(x)\ -\ \log_{10}(5)\)

Get the \(\displaystyle x\)-term on the left, the others on the right.

. . . \(\displaystyle \log_{10}(x) \;= \;\log_{10}(25)\ +\ \log_{10}(5)\)

. . . \(\displaystyle \log_{10}(x) \;= \;\log_{10}(25\cdot5)\)

. . . \(\displaystyle \log_{10}(x) \;= \;\log_{10}(125)\)

Take "anti-logs":

. . . . . . . . \(\displaystyle x \;= \;125\)

 

[latresa31s]

Thanks, to all of you . I was unble to get my calculator to work. I only got decimals. I had the problem set up right but I did not multiply. Thanks again

 

[Denis]

Quit blaming your calculator, LaStress

 

[latresa31s]

:lol: