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# (x - 1)(x)(x + 1)

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(x - 1)(x)(x + 1) [#permalink]  18 Mar 2018, 12:55
Expert's post
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Question Stats:

80% (00:18) correct 20% (00:12) wrong based on 10 sessions
 Quantity A Quantity B $$(x - 1)(x)(x + 1)$$ $$(x)(x)(x)$$

A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
[Reveal] Spoiler: OA

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Re: (x - 1)(x)(x + 1) [#permalink]  18 Mar 2018, 23:51
1
KUDOS
Explanation

Since the question does no explicitly states the range for x; x can be any number

Notice that If you put $$x =1$$ Qnty A becomes $$0$$
For $$X = 1$$ qty $$B = 1$$

Since Qty B is $$x^3$$. Notice that $$(-ve)^3$$ is -ve
IF $$x = -1$$ qty $$B = -1$$
Also notice that if $$X = -1$$ Qty A becomes 0
A can be greater than B or Less than B
option D
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This is my response to the question and may be incorrect. Feel free to rectify any mistakes

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Re: (x - 1)(x)(x + 1) [#permalink]  19 Mar 2018, 16:11
A: (x-1)(x)(x+1)= (x^2 -x)(x+1)= x^3 +x^2 -x^2 -x = x^3 -x
B: x^3
if x is negative then x^3 is negative and -x is something positive so x^3 -x is more than x^3 when x<0
if x is positive then x^3 is positive and -x is negative. so x^3-x is less than x^3 when x>0
As there is no upper or lower bound mentioned for x, we can't deduce which one is more or less and D is the answer.

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Re: (x - 1)(x)(x + 1)   [#permalink] 19 Mar 2018, 16:11
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