# easy log problem, did i get it right?

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• Apr 20th 2010, 12:44 AM
murkr
easy log problem, did i get it right?
problem #1 $log_{4} 24 - log_{4} 6$

problem #2 $
10log24 - log4$

im doing these two different ways, i kept getting two different answers, can someone please do these the right way so i can understand the procedure, thank you.

PS: when i type problem 1 in my cal i get the answer 1. but when i do it on paper i get the answer 4, and 1 & 4 are both an answer selection so i dont know which one it is. also, the directions says not to use a calculator though.

the directions say:
use the properties of logarithms to find the exact value of the expression. do not use a calculator.
• Apr 20th 2010, 12:51 AM
ADARSH
How about posting both your attempts..it will be more helpful.. we would be abe to tell you the place you went wrong ..
• Apr 20th 2010, 05:27 PM
murkr
Quote:

Originally Posted by ADARSH
How about posting both your attempts..it will be more helpful.. we would be abe to tell you the place you went wrong ..

in the first problem i crossed out the $log_{4}$ because they both had the same base which was 4. then i was left with 26 - 4 but i dont know what to do from there.

and then i couldnt do the second problem at all. sorry my attempts are not that good, i dont know the basics to well
• Apr 20th 2010, 05:34 PM
pickslides
Quote:

Originally Posted by murkr
in the first problem i crossed out the $log_{4}$ because they both had the same base which was 4. then i was left with 26 - 4 but i dont know what to do from there.

and then i couldnt do the second problem at all. sorry my attempts are not that good, i dont know the basics to well

The basics are very important in these problems

$\ln a - \ln b = \ln (a\div b)$

$\log_424- \log_46 = \log_4\frac{24}{6}=\dots$

Also recall

$\log_aa = 1$
• Apr 20th 2010, 05:35 PM
sa-ri-ga-ma
Quote:

Originally Posted by murkr
in the first problem i crossed out the $log_{4}$ because they both had the same base which was 4. then i was left with 26 - 4 but i dont know what to do from there.

and then i couldnt do the second problem at all. sorry my attempts are not that good, i dont know the basics to well

log(a) - log(b) in not equal to (a-b).
Go through the laws of multiplication and division in logarithm.
• Apr 20th 2010, 09:13 PM
murkr
Quote:

Originally Posted by pickslides
The basics are very important in these problems

$\ln a - \ln b = \ln (a\div b)$

$\log_424- \log_46 = \log_4\frac{24}{6}=\dots$

Also recall

$\log_aa = 1$

i can do it on my calulator, i do log(24) / log(4) = 2.29
and log(6) / log(4) = 1.29

i get the answer 1 which is answer A but i dont believe that this is the right answer because in the instructions it says dont use a calculator. can you please do the problem in steps, i find it easier for me to understand it better if i see someone do it. thanks again
• Apr 20th 2010, 09:24 PM
bigwave
use the rule mentioned
Quote:

Originally Posted by murkr
i can do it on my calulator, i do log(24) / log(4) = 2.29
and log(6) / log(4) = 1.29

i get the answer 1 which is answer A but i dont believe that this is the right answer because in the instructions it says dont use a calculator. can you please do the problem in steps, i find it easier for me to understand it better if i see someone do it. thanks again

your calculator asumes a log base of 10 so use the rule mentioned
• Apr 20th 2010, 09:39 PM
murkr
Quote:

Originally Posted by bigwave
your calculator asumes a log base of 10 so use the rule mentioned

im just not getting it im sorry..
when you solve the answer yourself without a cal what do you get?
• Apr 20th 2010, 09:56 PM
bigwave
$\log_424- \log_46 = \log_4\left(\frac{24}{6}\right)=\log_4{4}=1$
• Apr 20th 2010, 10:20 PM
murkr
Quote:

Originally Posted by bigwave
$\log_424- \log_46 = \log_4\left(\frac{24}{6}\right)=\log_4{4}=1$

yeah thats the answer i got from doing it on my cal, for some reason i thought doing it on paper would give me a different answer.

how do i put #3 in a calculator? with #2 i just type in log(24)/log(4) / log(6)/log(4) that equaled 1 for the answer.

but i dont know how to type in #3 can you help me with that? last qustion i promise :o
• Apr 21st 2010, 02:27 AM
ADARSH
Quote:

Originally Posted by murkr
problem #1 $log_{4} 24 - log_{4} 6$

problem #2 $
10log24 - log4$

im doing these two different ways, i kept getting two different answers, can someone please do these the right way so i can understand the procedure, thank you.

PS: when i type problem 1 in my cal i get the answer 1. but when i do it on paper i get the answer 4, and 1 & 4 are both an answer selection so i dont know which one it is. also,the directions says not to use a calculator though.

the directions say:
use the properties of logarithms to find the exact value of the expression. do not use a calculator.

Quote:

Originally Posted by murkr
i can do it on my calulator, i do log(24) / log(4) = 2.29
and log(6) / log(4) = 1.29

i get the answer 1 which is answer A but i dont believe that this is the right answer because in the instructions it says dont use a calculator. can you please do the problem in steps, i find it easier for me to understand it better if i see someone do it. thanks again

Quote:

Originally Posted by murkr
im just not getting it im sorry..
when you solve the answer yourself without a cal what do you get?

Quote:

Originally Posted by murkr
yeah thats the answer i got from doing it on my cal, for some reason i thought doing it on paper would give me a different answer.

how do i put #3 in a calculator
? with #2 i just type in log(24)/log(4) / log(6)/log(4) that equaled 1 for the answer.

but i dont know how to type in #3 can you help me with that? last qustion i promise :o

Your directions say: Don't use a calculator, so first of all
Send your calculator to Antarctica.

You should first of all solve your questions in a paper Here is Logarithm Tutorial.

Read the link given below(not completely but to your required level) and even then tell us if still need help

Logarithm - Wikipedia, the free encyclopedia