Question

Does anybody know how to solve this problem?
The question is log6(40)=

The choices are:
A) log10(6) + log10(40)
B) log10(6) - log 10(40)
C) log10(6) * log10(40)
D) log10(40) / log10(6)

The answer is D, but I don't understand how to find it.

Answer 1

you divide the big number by the small number! it just always works out that way!

Answer 2

LogB(a) = LogC(a) / LogC(B)

Log6(40) = Log10(40)/Log10(6)

Answer 3

ohhh, ok

Answer 4

but wait, what would the answer be if you divide Log10(40)/Log10(6?

Answer 5

oh and thank-you for helping me with at

Answer 6

oh wait wait wait

Answer 7

actually, how did u get log10(40) and log 10(6)?

Answer 8

For any log equation, you can use the base change rule.

LogB(a) = LogC(a) / LogC(B)

Here a was 40, b was 6. C could be anything you want it to be and it will work. Here they gave the option for 10

Answer 9

oh ok

Answer 10

and then, dividing it is the best way to solve?

Answer 11

Well if you want an actual value, simply plug it into a calculator. This rule is most often used because values for loge, and log10 are readily availble and it is much easier to compute log10(40) / log10(6) than log6(40).

So to solve yes you must divide. If you can do it using log tables go ahead. I'd just plug it into a calculator

Answer 12

oh ok, thanks