idontknowwhy94 wrote:
Is x<0?
1) \(x^{3} + x^{2}\) + x + 2 = 0
2) \(x^{2}\)-x-2 < 0
Keep the Kudos coming in and let the questions come out
Responding to a pm:
Quote:
For statement 1 it is clear that x >= 0 but when I tested -ve values I didn't find any which can satisfy the equation. Though I knew that x < 0, I continuously tried to find some -ve value that satisfied the equation. But it was a waste of time to find the value. How can I crack these type of traps on GMAT or it is my lack of understanding of concepts.
In stmnt 1, note that the point is that x cannot be positive or 0. So it has to be negative (since it has to be real).
If x is positive, all terms are positive and their sum cannot be 0.
If x is 0, you get 2 = 0 which is not valid.
So x has to be negative. No need to look for the actual value. It will not be an integer.
\(x^{3} + x^{2}+ x + 2 = 0\)
If you plug in x = -1, you get 1 = 0
If you plug in x = -2, you get -4 = 0
So somewhere in between -1 to -2, x will take a value such that you will get 0 = 0
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Karishma
Veritas Prep GMAT Instructor
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