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10 Oct 2017, 00:55
Kudos
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A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
(hard)
Question Stats:
46% (01:36) correct
54%
(01:25)
wrong
based on 67
sessions
History
Date
Time
Result
Not Attempted Yet
What is the value of |x - y|?
(1) \(–2xy – y^2 = x^2 – 4xy – 1\)
(2) \(x^2 – x = xy\)
(1) \(–2xy – y^2 = x^2 – 4xy – 1\)
(2) \(x^2 – x = xy\)
Pure algebraic questions like this one are no longer part of the GMAT Data Sufficiency syllabus.
For relevant Data Sufficiency questions, please check the Data Sufficiency forum:
Data Sufficiency Forum
Data Sufficiency Forum
10 Oct 2017, 01:55
Kudos
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IMO it's A.
Statement 1: rearrange to get the value of (x-y)^2 = 1.
Thus, |x-y|= 1.
Sufficient.
Statement 2: rearranging gives:-x(x-y-1) =0.
So, either x= 0. Thus, |x-y| = |y|. No definite value.
Or (x-y-1) = 0.
x-y = 1. |x-y| = 1.
Since, this statement gives multiple possibilities, its Not sufficient.
Hence, answer is A.
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Posted from my mobile device
Statement 1: rearrange to get the value of (x-y)^2 = 1.
Thus, |x-y|= 1.
Sufficient.
Statement 2: rearranging gives:-x(x-y-1) =0.
So, either x= 0. Thus, |x-y| = |y|. No definite value.
Or (x-y-1) = 0.
x-y = 1. |x-y| = 1.
Since, this statement gives multiple possibilities, its Not sufficient.
Hence, answer is A.
Posted from my mobile device
Posted from my mobile device
11 Oct 2017, 09:50
Kudos
Bookmarks
Statement 1 is sufficient for reasons explained above.
Statement 2 is also sufficient because equation can be written as
x(x-1) = xy --> Cross off x on both sides --> x-1=y --> x=y+1
Substitute above in question --> |x - y| = |y + 1 - y|=|1|=1
So answer is D
Statement 2 is also sufficient because equation can be written as
x(x-1) = xy --> Cross off x on both sides --> x-1=y --> x=y+1
Substitute above in question --> |x - y| = |y + 1 - y|=|1|=1
So answer is D
