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If x/|y| = -1 which of the following must be true? A) x = -y B) x = y
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11 May 2022, 02:00
11 May 2022, 02:00
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Question Stats:
62% (00:48) correct
37% (01:08) wrong based on 29 sessions
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If x/|y| = -1 which of the following must be true?
A) x = -y
B) x = y
C) x = y^2
D) x^2 = y^2
E) x^3 = y^3
A) x = -y
B) x = y
C) x = y^2
D) x^2 = y^2
E) x^3 = y^3
Part of the project: GRE Quantitative Comparison & Problem Solving Challenge
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GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
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Re: If x/|y| = -1 which of the following must be true? A) x = -y B) x = y
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11 May 2022, 06:10
11 May 2022, 06:10
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Carcass wrote:
If x/|y| = -1 which of the following must be true?
A) x = -y
B) x = y
C) x = y²
D) x² = y²
E) x³ = y³
A) x = -y
B) x = y
C) x = y²
D) x² = y²
E) x³ = y³
STRATEGY: Upon reading any GRE Multiple Choice question, we should always ask, Can I use the answer choices to my advantage?
In this case, we can easily test values that satisfy the given equation.
Now let's give ourselves up to 20 seconds to identify a faster approach.
In this case, we we might also try some algebraic manipulation, but it's not immediately clear how successful that would be.
So let's go with testing values.
It may take a little bit of testing to find some x- and y-values that satisfy the equation x/|y| = -1.
One possible solution is x = -2 and y = 2 (since (-2)/|2| = -1)
Now let's plug x = -2 and y = 2 into the five answer choices to see which ones are true. We get:
A) -2 = -2. TRUE. Keep.
B) -2 = 2. Not true. Eliminate.
C) -2 = 2². Not true. Eliminate.
D) (-2)² = 2². TRUE. Keep.
E) (-2)³ = 2³. Not true. Eliminate.
We're down to choices A and D.
Now let's find another pair of x- and y-values that satisfy the equation x/|y| = -1.
Another possible solution is x = -2 and y = -2 (since (-2)/|-2| = -1)
Plug x = -2 and y = 2 into the 2 remaining answer choices:
A) -2 = -(-2). Not true. Eliminate.
D) (-2)² = (-2)². TRUE. Keep.
Answer: D
Re: If x/|y| = -1 which of the following must be true? A) x = -y B) x = y
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23 May 2022, 00:31
23 May 2022, 00:31
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30sec approach.
From the given information, x=-|y|. This means that x and y have same values but their signs may vary. Thus x^2 must be equal to y^2.
Answer D.
From the given information, x=-|y|. This means that x and y have same values but their signs may vary. Thus x^2 must be equal to y^2.
Answer D.
