# Root equation help

arildno
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That's impossible.
you have most likely miscopied the original problem.

Ok, must of done. Now interestly the next question on the paper is

Hence or otherwise sove

$$\frac{1}{x-2} + \frac{2}{x+4} = \frac{1}{3}$$

so I will EXPAND the fractions (or cross multiply)?
this will give me

9x = x² - 2x + 4x - 8
so this is a quadratic. - 9x

x² -7x + 8 = 0
(x + 1)(x-8) = 0
so x = -1 or x= 8

that correct?

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arildno
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Which is a totally different issue altogether!
What you have there is an EQUATION, what you said before was that that equality was an IDENTITY (which is NOT correct).

aha i see
to solve it then

$$\frac{1}{x-2} + \frac{2}{x+4} = \frac{1}{3}$$

so I will EXPAND the fractions (or cross multiply)?
this will give me

9x = x² - 2x + 4x - 8
so this is a quadratic. - 9x

x² -7x + 8 = 0
(x + 1)(x-8) = 0
so x = -1 or x= 8

that correct?

arildno
Homework Helper
Gold Member
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Seems so, yes.

O, right first time...

Now here's a hard one I dont get

Find the value of

m when $$\sqrt{128} = 2^{m}$$

I no straight away from binary that 2^7 is 128 does that help?

arildno
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Indeed it helps!
Remember how roots can be written as exponents..

$$\frac{7}{2}$$

but how would i solve it normally?

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arildno
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Gold Member
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Indeed, that is what m equals, as soon as you get the LateX right..

but say if i didn't know about binary how would i got about solving it
somthing to do with surds isn't it?

HallsofIvy