# need help simplyfying

• Sep 23rd 2008, 07:21 AM
hana_102
need help simplyfying
$2x ^ {2+x}= \frac{1}{4^{x+1} }$
• Sep 23rd 2008, 07:47 AM
Moo
Hello,
Quote:

Originally Posted by hana_102
$2x ^2+^x= \frac{1}{4^x+^1}$

Please put brackets where it is necessary. Because I don't understand your notation of ^...

If you want to use the power, do :

$2^{power + brackets}$

:)
• Sep 23rd 2008, 07:59 AM
hana_102
Quote:

Originally Posted by Moo
Hello,

Please put brackets where it is necessary. Because I don't understand your notation of ^...

If you want to use the power, do :

$2^{power + brackets}$

:)

I tried that but it doesn't work, which brackets should i use? what its suppose to mean is x raised to the 2+x power , and 4 raised to x+1 power. does that make sense?
• Sep 23rd 2008, 09:10 AM
Soroban
Hello, hana_102!

I'm 99.99% sure there is a typo . . .

Quote:

$2^{2+x}\;=\;\frac{1}{4^{x+1}}$

We have: . $\left(2^{x+2}\right)\left(4^{x+1}\right) \;=\;1$

. . . . . . . $\left(2^{x+2}\right)\left(2^2\right)^{x+1} \;=\;1$

. . . . . . . $\left(2^{x+2}\right)\left(2^{2x+2}\right) \;=\;1$

. . . . . . . . . . . . $2^{3x+4} \;=\;1$

. . . . . . . . . . . . $2^{3x+4} \;=\;2^0$

. . . . . . . . . . . $3x + 4 \;=\;0$

. . . . . . . . . . . . . . $\boxed{x \;=\;\text{-}\frac{4}{3}}$

• Sep 23rd 2008, 09:14 AM
hana_102
Quote:

Originally Posted by Soroban
Hello, hana_102!

I'm 99.99% sure there is a typo . . .

We have: . $\left(2^{x+2}\right)\left(4^{x+1}\right) \;=\;1$

. . . . . . . $\left(2^{x+2}\right)\left(2^2\right)^{x+1} \;=\;1$

. . . . . . . $\left(2^{x+2}\right)\left(2^{2x+2}\right) \;=\;1$

. . . . . . . . . . . . $2^{3x+4} \;=\;1$

. . . . . . . . . . . . $2^{3x+4} \;=\;2^0$

. . . . . . . . . . . $3x + 4 \;=\;0$

. . . . . . . . . . . . . . $\boxed{x \;=\;\text{-}\frac{4}{3}}$

Hi,

Thank you for that.

Why are you 99.99% sure this is a typo? its the right equation.
• Sep 23rd 2008, 09:20 AM
Moo
Quote:

Originally Posted by hana_102
Hi,

Thank you for that.

Why are you 99.99% sure this is a typo? its the right equation.

It is not solvable a simple way if it is indeed $2x^{2+x}=4^{-x-1}$

Not to hurt you, it is not a high school level equation. You can only approximate the solution.
By the way, my TI-89 gives x=0.336346176422 after a 30-second calculation.