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Order of Operations

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Order of Operations

by ostrowskiamy » Mon Mar 25, 2013 5:33 pm
Hi folks! This is a seemingly-easy question, but the way the O.G. solves for "x" is different than I understood it to be...

Their process:

2x^2 = 400
x^2 = 200
etc.

Why do we not take the sq. root of the 400 first, to be left with 2x = sq.root(400)? I'm using PEMDAS to problem solve; why does that order not apply here?

Thanks so much in advance!
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by Anju@Gurome » Mon Mar 25, 2013 6:31 pm
ostrowskiamy wrote:Why do we not take the sq. root of the 400 first, to be left with 2x = sq.root(400)? I'm using PEMDAS to problem solve; why does that order not apply here?
It is given that 2x^2 = 400 NOT (2x)^2 = 400
Hence, if you take square root first it'll be (√2)x = √400 = 20

Hope that helps.
Anju Agarwal
Quant Expert, Gurome

Backup Methods : General guide on plugging, estimation etc.
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