# Thread: possibly a division log problem

1. ## possibly a division log problem

I think I might have to subtract?

3. ## Re: possibly a division log problem

You think? You should already have learned the "laws of exponents":
$\displaystyle a^na^m= a^{n+ m}$, $\displaystyle \frac{a^n}{a^m}= a^{n- m}a$, and $\displaystyle (a^n)^m= a^{mn}$.

5. ## Re: possibly a division log problem

Originally Posted by dtdj13
Is the answer 8^(2x)/2^(4x) = 4^(-2x)?
No ...

oh,yea ...parentheses!

$\dfrac{8^{2x}}{2^{4x}} = \dfrac{(2^3)^{2x}}{2^{4x}} = \dfrac{2^{6x}}{2^{4x}}$

finish it ...

6. ## Re: possibly a division log problem

it is a multiple choice question the answers are 2^x, 4^X, 2^-2x,4^-2x i got 2^2x which isn't one of the choices.

7. ## Re: possibly a division log problem

Again using the "laws of exponents", $\displaystyle 2^{2x}= (2^2)^x$. Learn the laws of exponents!

8. ## Re: possibly a division log problem

Originally Posted by dtdj13
it is a multiple-choice question the answers are 2^x, 4^X, 2^-2x,4^-2x i got 2^2x which isn't one of the choices.
No, use parentheses (as in the following):

... the answers are 2^x, 4^x, 2^(-2x), 4^(-2x). I got 2^(2x), which isn't one of the choices.

Suppose the actual answer is equivalent to 2^(2x), which is what you figured.

Can you convert that to one of the answer choices?

$\displaystyle 2^{2x} \ = \ 2^{2(x)} \ = \ (2^2)^x \ = \ ?$

9. ## Re: possibly a division log problem

Originally Posted by dtdj13
it is a multiple choice question the answers are 2^x, 4^X, 2^(-2x),4^(-2x) i got 2^(2x) which isn't one of the choices.
parentheses ...
parentheses ...
parentheses ...
parentheses ...

btw, did I say ...

parentheses ... ?

10. ## Re: possibly a division log problem

is the answer equivalent to 4^x? or is it 2^x

btw I don't how to use parentheses outside of using them in a calculator

11. ## Re: possibly a division log problem

put away the calculator ...

$(\color{red}{2^2})^x = (\color{red}{4})^x = 4^x$

12. ## Re: possibly a division log problem

The conventions for use of parentheses in a calculator and anywhere else are the same.

Failure to use parentheses where they are needed will cause you to get erroneous answers.