Problem set question from Manhattan 12th - newby question

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Problem set question from Manhattan 12th - newby question [#permalink]

31 May 2012, 06:51

I've encounter a problem in GMAT Manhattan which I don't get.
This is a quadratic equation.
Given that d/4 + 8/d + 3 = 0 , what is d?

In the solution they say you multiply the entire equation with 4d and thus come up with d^2 + 32 + 12d. But how? I can find how especially d4 can become d^2 by doing that.

Would like to know a solution step by step.

Last edited by jonatande on 31 May 2012, 07:09, edited 1 time in total.

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Re: Problem set question from Manahttan - newby question [#permalink]

31 May 2012, 07:02

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jonatande wrote:

If you multiply \frac{d}{4} + \frac{8}{d} + 3 = 0 by 4d you'll get: \frac{d}{4}*4d + \frac{8}{d}*4d + 3*4d = 0*4d --> d^2+32+12d=0 --> d=-8 or d=-4.

Hope it's clear.
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Re: Problem set question from Manahttan - newby question [#permalink] 31 May 2012, 07:02

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Problem set question from Manhattan 12th - newby question

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Problem set question from Manhattan 12th - newby question

Problem set question from Manhattan 12th - newby question

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