If x and y are negative numbers, what is the value of (x^2)/x − (y∗|y|)^.5?
A) 1+y
B) 1−y
C) −1−y
D) y−1
E) x-y
OA:D
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If x and y are negative numbers,
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fiza gupta
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The problem has been transcribed incorrectly.
It should read as follows:
Plugging these values into (√x²)/x − √(-y|y|), we get:
(√9)/(-3) − √(2|-2|) = 3/-3 - √4 = -1 - 2 = -3.
The target value is -3.
Now y=-2 into the answers to see which yields -3.
Only D works:
y-1 = -2-1 = -3.
The correct answer is D.
It should read as follows:
Let x=-3 and y=-2.If x and y are negative numbers, what is the value of (√x²)/x − √(-y|y|)?
A) 1+y
B) 1−y
C) −1−y
D) y−1
E) x-y
Plugging these values into (√x²)/x − √(-y|y|), we get:
(√9)/(-3) − √(2|-2|) = 3/-3 - √4 = -1 - 2 = -3.
The target value is -3.
Now y=-2 into the answers to see which yields -3.
Only D works:
y-1 = -2-1 = -3.
The correct answer is D.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
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Jay@ManhattanReview
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We have to find out the value of (√x²)/x - √(-y|y|).fiza gupta wrote:If x and y are negative numbers, what is the value of (√x²)/x - √(-y|y|)?
A) 1+y
B) 1-y
C) -1-y
D) y-1
E) x-y
OA:D
Since x and y are negatives, we can write (√x²)/x as |x| / (-|x|) = 1/(-1) = -1
Similarly, we can write √(-y|y|) as √(|y|.|y|) = √(|y|^2) = |y|
Thus, (√x²)/x - √(-y|y|) = -1 - |y|
Since y is negative, we can write -1 - |y| as -1 + y.
Answer: D
Hope this helps!
-Jay
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Hi fiza gupta,
TESTing VALUES is really useful in these types of situations; Mitch showcased that approach perfectly, so I won't rehash any of that work here. Instead, I want to point out that it's important to remember that math functions are based on a finite set of rules, so when you see a question that includes squares, square roots, absolute values, etc. you should not get overly emotional about it. Instead, think about what the rules 'mean' - and jotting down a few simple examples on the pad can help. In that way, you can focus on the patterns and Tactics that can be used to answer the question, and not be bogged down trying to decipher how all of these functions will interact with one another.
GMAT assassins aren't born, they're made,
Rich
TESTing VALUES is really useful in these types of situations; Mitch showcased that approach perfectly, so I won't rehash any of that work here. Instead, I want to point out that it's important to remember that math functions are based on a finite set of rules, so when you see a question that includes squares, square roots, absolute values, etc. you should not get overly emotional about it. Instead, think about what the rules 'mean' - and jotting down a few simple examples on the pad can help. In that way, you can focus on the patterns and Tactics that can be used to answer the question, and not be bogged down trying to decipher how all of these functions will interact with one another.
GMAT assassins aren't born, they're made,
Rich
