# Thread: write log as an expression

1. ## write log as an expression

I get what the question asks for, i just dont get how to do it.

Write an expression for the following, by using a sum/difference and/or a multiple:

i think i got it, but im not sure:

loga5a^4
= loga5 + logaa^4
= loga5 + 4logaa

is there a way to reduce logaa?

2. Originally Posted by snypeshow
I get what the question asks for, i just dont get how to do it.

Write an expression for the following, by using a sum/difference and/or a multiple:

hints...

$\log(xy) = \log(x) + \log(y)$

and

$\log_b(b^n) = \textcolor{red}{n}$

3. yeah, i used both those identities. i edited my original post right after you posted

4. Originally Posted by snypeshow
I get what the question asks for, i just dont get how to do it.

Write an expression for the following, by using a sum/difference and/or a multiple:

i think i got it, but im not sure:

loga5a^4
= loga5 + logaa^4
= loga5 + 4logaa

is there a way to reduce logaa?
remember the identity, that:
logaa=1
loga1=0