If x < 0, lxl is -x.
Or sqrt(-xlxl) is sqrt(-x*-x) = sqrt(x^2).
In GMAT only the positive value of square root is taken.
Note that since x<0, -x is positive.
So even though both -x and x square up to give x^2, we take only the value -x as sqrt(x^2).
The correct answer is (A).
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Gurome, Inc.
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Let x = -2.
Then √(-x * |x|) = √[-(-2) * |-2|] = √(2*2) = √4 = 2.
Now we plug x = -2 into all the answer choices to see which gives us our target answer of 2.
Only answer choice A works:
-x = -(-2) = 2.
The correct answer is A.
Then √(-x * |x|) = √[-(-2) * |-2|] = √(2*2) = √4 = 2.
Now we plug x = -2 into all the answer choices to see which gives us our target answer of 2.
Only answer choice A works:
-x = -(-2) = 2.
The correct answer is A.
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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.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
