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(3x+1)((3x-1) or 9x^2
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27 Oct 2020, 06:43
27 Oct 2020, 06:43
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Question Stats:
89% (00:27) correct
10% (01:41) wrong based on 28 sessions
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Quantity A |
Quantity B |
\([3x+1][3x-1]\) |
\(9x^2\) |
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.
Source: 320 GRE Math Questions
Re: (3x+1)((3x-1) or 9x^2
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27 Oct 2020, 17:51
27 Oct 2020, 17:51
1
quant A : (3x+1)((3x-1)= \(9x^2 -1\)
quant B :\(9x^2\)
quant A= (quant B)-1
so quant A < quant B
option B is correct
quant B :\(9x^2\)
quant A= (quant B)-1
so quant A < quant B
option B is correct
Re: (3x+1)((3x-1) or 9x^2
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13 Nov 2020, 20:50
13 Nov 2020, 20:50
1
Question A
(3x+1)(3x-1)
= 9x^2-3x+3x-1
= 9x^2-1
Question B
9x^2
Divide both sides by 9X^2
9X^2/9x^2-1 -----------Question A
= -1
9x^2/9x^2 --------------Question B
= 1
Hence, comparing A to B makes B greater.
The correct answer is B
(3x+1)(3x-1)
= 9x^2-3x+3x-1
= 9x^2-1
Question B
9x^2
Divide both sides by 9X^2
9X^2/9x^2-1 -----------Question A
= -1
9x^2/9x^2 --------------Question B
= 1
Hence, comparing A to B makes B greater.
The correct answer is B
