- Thread starter
- #1

#### Petrus

##### Well-known member

- Feb 21, 2013

- 739

I am stuck on this equation and don't know what to do, If i take ln it does not work, any advice?

\(\displaystyle 16•4^{-x}=4^x-6\)

Regards,

\(\displaystyle |\pi\rangle\)

- Thread starter Petrus
- Start date

- Thread starter
- #1

- Feb 21, 2013

- 739

I am stuck on this equation and don't know what to do, If i take ln it does not work, any advice?

\(\displaystyle 16•4^{-x}=4^x-6\)

Regards,

\(\displaystyle |\pi\rangle\)

- Jan 26, 2012

- 644

$$16 = (4^x)^2 - 6 \cdot 4^x$$

Now substitute $u = 4^x$. What do you see?

- Feb 13, 2012

- 1,704

Set $4^{x}=y$, then solve for y and finally find $x = \frac{\ln y}{\ln 4}$ ...

I am stuck on this equation and don't know what to do, If i take ln it does not work, any advice?

\(\displaystyle 16•4^{-x}=4^x-6\)

Regards,

\(\displaystyle |\pi\rangle\)

Kind regards

$\chi$ $\sigma$

- Thread starter
- #4

- Feb 21, 2013

- 739

Thanks for the fast respond and help from you both! i succed to solve it with correct answer!

Regards,

\(\displaystyle |\pi\rangle\)