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If x = -1, (OG16)

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by [email protected] » Thu May 19, 2016 4:47 pm
Hi boomgoesthegmat,

This question is just about making sure that the arithmetic is done correctly (and that we don't lose track of the "minus signs"...

Plugging X = -1 into the given equation, we end up with....

[+1 - (-1) + 1]/[-1 -1] =
[1 + 1 + 1]/[-2] =
[3]/[-2]

Final Answer: A

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Last edited by [email protected] on Fri May 20, 2016 9:45 am, edited 1 time in total.
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by OptimusPrep » Thu May 19, 2016 8:08 pm
boomgoesthegmat wrote:If x = -1, then (x^4 - x^3 + x^2)/(x-1) =

A) -3/2
B) -1/2
C) 0
D) 1/2
E) 3/2

OA: A
In such question, always remember
Even power of negative sign = positive,
Odd power of negative sign = negative.

On plugging x = -1 in (x^4 - x^3 + x^2)/(x-1),
we get (x^4 - x^3 + x^2)/(x-1) = (1 + 1 + 1)/ -2 = -3/2

Correct Option: A
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