# How do you evaluate this log equation?

## Homework Statement

log39 + log41/64 + log51

none

## The Attempt at a Solution

I tried answering it by...

(3x=9) + (4x=1/64) + (5x=1)
because of this, I got 5. Is that correct?

## Answers and Replies

tiny-tim
Science Advisor
Homework Helper
Hi haengbon!
(3x=9) + (4x=1/64) + (5x=1)
because of this, I got 5. Is that correct?

Correct method , but wrong result

try (4x=1/64) again.

Hi haengbon!

Correct method , but wrong result

try (4x=1/64) again.

I tried it again and got -3 for 4x=1/64 :D is that correct now? ^^ thank you for the help by the way :)

tiny-tim
Science Advisor
Homework Helper
I tried it again and got -3 for 4x=1/64 :D is that correct now? ^^

Yup!

Mark44
Mentor
haengbon said:
I tried answering it by...

(3x=9) + (4x=1/64) + (5x=1)
because of this, I got 5. Is that correct?
If you turn in work like this, your instructor will probably deduct points, since you are apparently trying to add three equations.

Each of the log expressions is simple enough to calculate, so your work should look something like this.

log39 + log41/64 + log51
= 2 - log464 + 0
= 2 - 3 = -1

I used the fact that log(1/x) = - log(x) going from the first expression to the second.