1. ## logarithm equation

can someone please write back to me as soon as possible with the answer and working to this question, its got me totaly baffled!!

2log21/x + 3log2x = 4

2. Hello,

Originally Posted by jammy14
can someone please write back to me as soon as possible with the answer and working to this question, its got me totaly baffled!!

2log21/x + 3log2x = 4
$\log \frac 1x=-\log x$

Therefore, the equation becomes :

$-2\log_2 x+3 \log_2 x=4$

$\log_2 x=4$

---> $\underbrace{2^{\log_2 x}}_{x}=2^4$

$\boxed{x=16}$

3. thankx but could you please explain how you did the last bit-

--->

im not so good at this!!

4. Originally Posted by jammy14
thankx but could you please explain how you did the last bit-

--->

im not so good at this!!
Ok

Basically, $\log_a x=b$ means that $x=a^b$

Or you can remember that $a^{\log_a x}=x$

These are basic rules

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For the latter part, $2^4=16$

5. thankx